Mayor Walter E. Washington officially launched his campaign for reelection yesterday by asking city voters to choose someone with proven experience and personal integrity - that's me," he said - rather than a new "miracle mayor" claiming the power to "whisk away every problem to bring instant solutions."

During his past 10 years in office, the mayor said, he had forged a "stronger community" out of the "rubble of destroyed buildings and seared human relationships" in the city following the riots of 1968.

He portrayed his two principal opponents for the Democratic nomination in the Sept. 12 primary - City Council Chairman Sterling Tucker and council member Marion Barry - as people who talk but not do.

"I am proud of the achievements and changes of the last 10 years, and the people of this city can be proud . . . They represent ongoing change - solid change and not just talk," he told a wildly enthusiastic group of about 500 supporters at the Hotel Washington downtown.

"I am not claiming that we are perfect, that I am the mayor of a mythical city," he said. "But I am saying that I am the mayor of a real city, with real problems, that require reals solutions through hard work and leadership, not just simple rhetoric."

The announcement placed a stamp of officialdom on a campaign that really began months ago, and it was a well-orchestrated event. There were blue - and - white "Washington for Washington" buttons and banners and red-white-and-blue bunting draped on in the hall. There was southern Baptist political preaching to warn up the audience and a recording of a rocking disco version of Ray Charles singing "I Can See Clearly Now" at the rally's end.

The mayor, who could hardly sit still while waiting to be introduced, mimicked a jogger in action when he approached the microphone - to indicate that he was in fact "running." After his 30-minute speech, he invited supporters to come up to the stage, and they swarmed into the aisles to do so, many asking for his autograph on left-over 1974 campaign pictures that had been given to some in the crowd earlier yesterday.

Some of those present were senior citizens and community people who had been bused in on United Planning organization and private owned buses. Others were city employes ostensibly on their lunch hour - at least one of whom boastfully showed a reporter an annual leave slip signed by the mayor to indicate that he was not engaging in political activity on city time.

For many of the mayor's faithful followers on hand, it was a long-awaited affirmation that the 63-year-old Washington had decided to defy the political obituaries written about him less than two years ago.

"The city is Washington. The hotel is Washington and the mayor is Washington," said the Rev. Andrew H. Fowler, minister of Capital View Baptist Church and executive secretary of the Committee of 100 Ministers, a clergy group that has long backed the mayor.

The Rev. Andrew J. Allen, minister for the First Baptist Church of Deanwood, beamed a broad smile and joked, "Tucker better tuck his head and go somewhere else."

The mayor launched his campaign with visibly strong support from two of his strongest allies - the city's organized labor groups and black clergymen.

Top officers of the Greater Washington Central Labor Council, which has already endorsed the mayor's candidacy, as well as the Labor council's past president, J.C. Turner, a long-time backer of the mayor, were president.Ron Richardson, executive secretary of Local 25 of the Hotel and Restuarant Employees Union, presented the mayor with a check for $2,000 and said $2,000 more would soon be coming from the organization's national political committee.

One of the most well-received ministers present actually said nothing, but was warmly applauded and when introduced. He was the Rev. Samuel Kelsey, pastor of the Temple Church of God in Christ and presiding bishop over some 22 churches of that denomination in the city. Kelsey's presence represented a political coup for the mayor.

Only five days ago, Kelsey, who now sat behind the mayor, had sat at the same table with Tucker, ostensibly as part of a group of nearly six dozen churchmen supporting Tucker's candidacy.

On the following day, however, Kelsey said he had been "double-crossed" into appearing at the table. "I didn't never make any commitment. I didn't say anything." Kelsey said then. "Washington is my man. I don't care who you saw me with."

Although the city's business community gave the mayor its overwhelming support in 1974 - and especially its contributions - there were few of them present at yesterday's rally. The only ranking member of the Metropolitan Washington Board of Trade present was John B. Duncan, the mayor's longtime friend and political tutor, who is secretary of the Board of Trade.

Wilhelmina J. Rolark (D-Ward 8) was the only member of the City Council who sat at the stage with the mayor. Council member Douglas E. Moore, a strong Washington supporter who is running for council chairman, was introduced and waved enthusiastically from the back of the room.

At-large Council member Jerry A. Moore Jr., Republican and Baptist minister who also was listed as a clergyman for Tucker Monday, was at the rally, telling reporters he was now neutral. Council member John A. Wilson (D-Ward 2) was also there. Wilson said he was not supporting anyone for mayor.

The mayor's verbal attacks yesterday named no one in particular, but most seemed to be aimed at Tucker and Del. Walter E. Fauntroy (D-D.C.). Fauntroy hand-picked Tucker as his political protege and mayoral candidate and said he wants to develop a well-strucutred Democratic Party organization in the city - ostensibly with himself at its head.

Washington portrayed himself as a "leader who has tried his best" and was not controlled by "special interests nor aspiring political bosses who call down from on high and say, 'You do it.'"

He took sharp issue with Tucker's campaign pledge to get the city full voting representation in Congress within five years, to end drug traffic in the city, and to curb pornography. "Anyone who runs for mayor of an American city and suggests that he will immediately turn everything around from wiping out all drug traffic to guaranteeing full voting rights cannot be taken seriously," the mayor said.

"As soon as he walks out all the prositutes are gonna leave?" the mayor asked. They said that 2,000 years ago.The amazing thing about it is if they (Tucker and Barry) could do it, why are they waiting until they get elected?"

The accomplishments of his administration logged by Washington in his speech yesterday included construction of 5,000 housing units in various parts of the city and the building of many new schools, recreation centers, libraries and swimming pools. "No longer do we apologized for hand-me-down buildings, relics of the old days of segregation and deprivation," he said.

The city's crime rate has been cut in half and D.C. completed the last fiscal year without a deficit budget on the books, the mayor said.

Women are working in many areas of city government, a "disruptive freeway program" has been halted and its money is being used for Metro construction, the mayor said. The city also has a new university, a "strong" office of consumer affairs and has expanded its medical services under his leadership he claimed.

The aggressive political style displayed by the mayor yesterday represents a sharp departure from his manner of less than two years ago, when his administration was under constant criticism and the mayor said little publicly.

His administration had been blemished by accusations of mismanagement against Joseph P. Yeldell, who was then director of human resources, and the mayor's handling of the Yeldell situation was a point of constant criticism. Citizens complained about late and inaccurate water bills, businessmen moaned that the mayor was inaccessible and Washington was viewed as a withdrawn, lifeless and slow-acting chief executive being run by his own government.

Some mayoral confidants said those were the "low points" of the Washington administration. A few old friends urged the mayor not to seek reelection. One top aide confided then that if an election were held at that time, the mayor would undoubtedly lose.

The other announced candidates in the Democratic primary include John L. Ray, Dorothy Maultsby, Richard A. Jackson, Charles S. (Trummie) Cain and James Clark.