Sen. Bob Packwood of Oregon, whose outspoken criticism of President Reagan has angered the White House, yesterday was unseated as chairman of the Republican senatorial campaign committee by Sen. Richard G. Lugar of Indiana, a Reagan loyalist.

The 54 Republican senators, casting secret ballots, voted 29 to 25 for Lugar.

He was nominated for the post by Sen. Paul Laxalt (Nev.), Reagan's best friend in the Senate, and White House officials were privately exuberant about his victory.

The move puts Republican campaign machinery and the millions of campaign dollars it controls firmly in the hands of conservative Reagan loyalists. As the 1984 elections approach, there will be no mavericks in campaign leadership posts to question Reagan's political choices and decisions.

Laxalt was recently selected as "general chairman" of the party by the president. Frank Fahrenkopf, the current Nevada state GOP chairman and a Reagan loyalist who is close to Laxalt, is to replace Richard Richards as chairman of the Republican National Committee. The third major GOP fund-raising organization, the National Republican Congressional Committee, is headed by Rep. Guy Vander Jagt (Mich.), another Reagan supporter.

Democrats, also reorganizing for the next session of Congress, reelected their leadership team, but Sen. Edward M. Kennedy (Mass.) moved to the Armed Services Committee and Sen. John C. Stennis (Miss.) went to the Appropriations Committee as part of a game of musical chairs for senior Democrats who changed their committee assignments.

After the Republican vote, Packwood and Lugar downplayed the importance of the Senate campaign committee change but the White House unhappiness with Packwood was reinforced by widespread complaints about him by many conservative contributors to the party. A letter from beer baron Joseph Coors supporting Lugar was circulated before the vote and Howard Wilkens, a Wichita, Kan., millionaire, had worked in his behalf.

Packwood, the letter said, "has used contributions from conservative Republicans like you to undermine the president."

Lugar, who drew his strongest support from conservatives, said Laxalt had not mentioned Packwood's problems with the White House in his nominating speech.

"He said I was tactful and diplomatic," said the Indiana Republican, who easily won a second term last month.

"It was not an ideological or personal conflict," Lugar insisted. "It was not a product of a White House purge."

The campaign committee -- its formal name is the National Republican Senatorial Committee -- vote was taken behind closed doors in the small, ornate chambers the Senate occupied from 1810 to 1859, normally just a stopping place for tourists in the Capitol.

In the same meeting, Republicans reelected their Senate leadership team, including Majority Leader Howard H. Baker Jr. (Tenn.), Majority Whip Ted Stevens (Alaska), and James A. McClure (Idaho), chairman of the Republican Conference of the Senate. All were unopposed.

On the Democratic side, also reelected without opposition were Minority Leader Robert C. Byrd (W.Va.), Minority Whip Alan Cranston (Calif.) and Daniel K. Inouye (Hawaii) as secretary of the Democratic Conference.

Packwood, a moderate, and Lugar, a conservative, emerged arm-in-arm from the GOP caucus in a show of party unity. Packwood said he did not think his defeat was due to the White House and that he felt no bitterness toward the administration.

Packwood, who raised $48 million as chairman during the last two years, ran afoul of the president for opposing the White House on the sale of Airborne Warning and Control System (AWACS) planes to Saudi Arabia and administration efforts to restrict legalized abortion.

He also drew cries of outrage from Reaganites by accusing the president of endangering the future of the Republican Party by advocating policies that alienated blacks, women, Hispanics and Jews.

Yesterday he said he had no regrets. He said he still feels the GOP must broaden its base because white males earning more than $40,000 a year made up the only group that gave the Republicans a majority in 1982.

"We lost everyone else," Packwood said.

Lugar agreed, in part, and pledged he, too, would "say things to the president that I think the president needs to hear."

The vote did not break along ideological lines. Sen. Barry Goldwater (Ariz.), for example, cast a proxy vote for Packwood. And party spokesmen said a crucial factor was a feeling that the chairmanship should be rotated every two years.

In the November election, Senate Republicans retained their 54-to-46 majority, but 19 GOP incumbents are up in 1984 and several are considered vulnerable.

On the other side of the aisle yesterday, several senior Democrats switched committee assignments, according to sources.

Kennedy went on the Armed Services Committee. Stennis replaces Sen. William Proxmire (Wis.) as ranking minority member of the Appropriations Committee, giving up the top spot on the Armed Services Committee. Sen. Henry M. Jackson (Wash.) moves into this slot and Proxmire is to become the ranking minority member of the Banking Committee, replacing Sen. Donald W. Riegle Jr. (Mich.).

Sen. Ernest F. Hollings (S.C.) reportedly is trading his position as ranking minority member of the Budget Committee for the same spot on the Commerce, Science and Transportation Committee.