The House yesterday strongly seconded President Carter's assertion that the United States should not take part in the Olympics in Moscow this summer unless Soviet troops are withdrawn from Afghanistan within a month. The vote on the nonbinding resolution was 386 to 12.

Then the House and Senate combined in a second slap at the Soviet Union, approving a joint resolution to normalize trade relations with China, thereby giving it a status never accorded the Soviet Union.The House vote on this was 294 to 88. The Senate vote was 74 to 8.

The votes were Congress' first official response to the Soviet invasion of Afghanistan last month and to Carter's appeal for decisive U.S. action in reply, most recently in his State of the Union address Wednesday night.

The Olympics resolution was the single most important nonmilitary sanction" that Congress could come up with to convince the Soviets to remove their troops from Afghanistan, said House Foreign Affairs Committee Chairman Clement J. Zablocki (D-Wis.) in pushing for adoption of the resolution.

The Senate is also expected to give overwhelming support to Carter's position on the Olympics. But it appeared that the Senate would not act until early next week, despite a personal plea from Carter to the Senate leadership for joint action on the resolution before this Saturday's meeting of the U.S. Oympic Committee. Legally, it is up to the USOC to decide whether to participate in the games.

The Senate Commerce Committee approved the House resolution yesterday. However, Senate Foreign Relations Committee Chairman Frank Church (D-Idaho) had scheduled hearings on several Senate-sponsored Olympics resolutions next week. An aide to Senate Majority Leader Robert C. BYRD (D-W. Va.) said yesterday that Senate action is not expected before next week.

The administration had hoped for a strong show of support from both houses before the USOC's executive board meeting Saturday in Colorado Springs to consider the president's request.

On Wednesday, USOC President Robert J. Kane told the Foreign Relations Committee that he saw "no way that the USOC would reach a decision contrary to that of the president and the Congress." However, an Associated Press poll of the 47-member Athletic Advisory Committee to the USOC showed that 20 of 32 respondents wanted the United States to stay in the Moscow Games, while six backed Carter's position. The rest were undecided or declined comment.

The House resolution calls on the USOC to honor Carter's request and to propose that the International Olympic Committee (IOC) transfer or cancel the 1980 Summer Olympics. It urges the USOC and Olympic committees of other countries to stay away from the Moscow Games and conduct alternative games of their own if the IOC rejects the request as IOC President Lord Killanin has indicated it would do.

The resolution took note of the U.N. General Assembly's condemnation of the Soviet invasion of Afghanistan, and said it "endangers independent countries neighboring Afghanistan and endangers access to a major source of the world's oil supplies," and hence both the security of the United States and the world.

The dozen House members who opposed the resolution came from all across the liberal-conservative spectrum.Most complained that it would be counterproductive.

In the strongest denunciation of the resolution, Rep. Ronald V. Dellums (D-Calif.) called it a "hysterical response, a symbolic empty gesture" that would plunge the Olympic games even further into politics.

Rep. William F. Goodling (R-Pa.) said he objected to the move as too hasty, suggesting that the USOC should be allowed to work quietly, without government pressure, to convince other countries' committees to relocate the Games outside the Soviet Union.

But Rep. William S. Broomfield (R-Mich.) argued that it would be an "impressive message of contempt to the Soviet for their barbaric action," and Rep. John Buchanan (R-Ala.) described the issue of one of "crime, not politics." Said Buchanan: "it's time for the world to stand up and say 'no' to crime. . . and 'no' to Moscow."

The trade-normalizing measure would restore most-favored-nation treatment to the People's Republic of China, meaning it would be able to export products to the United States under favorable tariffs granted to most of America's trading partners, a status it lost during the Korean War.

State Department officials have estimated that the new China trade pact could more than double commerce between the United States and China by 1985, and House Ways and Means Committee Chairman Al Ullman (d-Ore.) said yesterday that it would increase U.S. exports by $3 billion over the next five years.

Ullman called it "an historic occasion, a turning point in our relations with the most populous nation of the world." Opponents argued that China has yet to prove its peaceful and humane intentions. The United States should not "overreact to Afghanistan by hastily playing this so-called China card," said Rep. Richard T. Schulze (R-Pa.).

The administration considered but then bandoned plans to extend most-favored-nation treatment to the Soviet Union as well as China, even before the Afghanistan invasion. Speedy action on the China trade pact was intended as another signal of U.S. concern over Soviet expansionism, according to Byrd.