An indignant, unyielding Edward M. Kennedy pledged today will that he and his 1,200 delegates will wage a floor fight at the Democratic National Convention against the proposed party platform drafted by a committee dominated by supporters of President Carter.

Complaining that "a dominant faction" had put together a platform "that on essential questions is Democratic only in name," Sen. Kennedy (D-Mass.) said his forces "will walk and work the floor of the convention" to win more liberal positions on economic, energy and civil rights matters.

After noting that Carter had failed to follow some major planks of the party's 1976 platform, Kennedy also proposed a new party rule that would require each presidential candidate to state in writing his objections to the party platform before his name could be placed in nomination.

Kennedy acknowledged that the Carter forces, with about 2,000 delegates pledged to support the president, will outnumber Kennedy's troops at the convention. But he said the delegates "have a higher commitment than to vote for a candidate; they have a commitment to vote their conscience . . ."

The effort to convince Carter-pledged delegates to cast "conscience" votes against the president on rules or platform fights is the heart of Kennedy's uphill battle to win the Democratic nomination.

He hopes an anti-Carter mutiny on the rules or the platform will prompt hundreds of Carter-pledged delegates to switch to Kennedy when they vote on the nomination.

"I recognize the odds are against me," Kennedy said, but his tough speech today bore no hint of surrender. He excoriated Carter and the proposed platform in scornful tones, and his audience -- delegates to the international convention of the Service Employes union -- stood on chairs and tables to cheer and wave bright blue posters that read "Kennedy All the Way."

Whether or not Kennedy can garner the delegate strength to prevail in a convention fight, he will almost surely have enough delegates to force floor debate on major platform issues. And he said today he expects to do so.

"The jobless do not have seats on the committees of the Democratic convention," he said, "but my campaign does. The families without adequate health care and winter heat do not have floor passes . . . but my campaign does. The farmers who have lost their land do not have a place on the podium or a microphone . . . but my campaign does.

"And from that place and that microphone, we will speak for all of them."

In his speech, Kennedy set forth several specific areas in which he found the proposed platform unacceptable. But in a news conference afterward, he indicated that he might not wage a floor fight on every point.

His speech said the convention "must demand" a pledge that the Democratic nominee will not fight inflation with policies that cause unemployment, and will establish an immediate federal program to put 800,000 unemployed people back to work. It called for legal controls on wages and prices to freeze inflation, reenactment of price controls on oil products, and a promise to set up a comprehensive federal health insurance plan "by a date certain."

Kennedy's backers put forth all these demands last week when the platform committee met. Carter supporters on the committee voted all of them down by healthy margins.

After today's speech, reporters asked Kennedy if he really means to mount a convention fight on each of these issues.

"I can't pledge at this time that every single one of them will be moved forward," he said. "But I think the central economic ones will, will certainly, be advanced."

Much of the speech today consisted of a travelogue of Kennedy's campaign, in which he contrasted his strenuous eight-month pursuit of the Democratic nomination to Carter's decision to remain in the White House.

"I saw the families who live in the shadow of Three Mile Island," Kennedy said. "The Democratic Party must reject the idea that an official hundreds of miles away can determine that a near-meltdown is not dangerous to their health.

"Outside Los Angeles . . . I talked with [laid-off] rubber workers . . . It may be easy for government officials in the stately buildings of Washington, far from the smell of a rubber plant, to decide the time has come in the fight against inflation to force other men and women to lose their jobs.

"And I have talked with an elderly grandmother . . . in East Oakland, who has given up her telephone so she can pay the rent for her apartment. High officials with 10 telephone lines . . . have no right to tell that woman to sacrifice her lifeline to her grandchildren as part of the battle against inflation."