President Reagan, touching off another round of confrontation with Congress over environmental issues, yesterday vetoed legislation authorizing the Environmental Protection Agency's research program.

In his 10th veto since taking office, the president objected to the measure on the grounds that it would make a "political entity" out of the agency's scientific advisory board by requiring that it include consumer, labor, industry and academic members.

The president said this would be "a major step backward" that would "undermine the use of scientific knowledge" in making EPA rules.

The legislation's chief sponsor, Rep. James H. Scheuer (D-N.Y.), chairman of the House Science and Technology subcommittee on natural resources, called the veto "political" and said it was intended to gut long-term research into such topics as hazardous waste, acid rain, indoor air quality and groundwater pollution.

The legislation passed the House 314 to 92 and cleared the Senate on a voice vote. A spokesman for Scheuer said a "strong effort" would be made when Congress returns in special session Nov. 29 to override the veto.

A White House official said yesterday that the composition of the scientific advisory board was Reagan's chief objection. The legislation requires that this key advisory group include members from the states, industry, labor, academia, consumers and the general public.

Reagan said in his veto message that this requirement for "labels" on the board "is a modern-day version of Lysenkoism to which I must strongly object."

(Webster's New World Dictionary defines Lysenkoism as "a repudiated doctrine that characteristics acquired through environmental changes can be transmitted by heredity." The dictionary says it was "promoted" by T.D. Lysenko, a "Soviet agronomist" born in 1898.)

The president complained that the bill would inject "interest group politics" into the scientific process, and noted that interest groups would, by law, have an opportunity to make their views heard at other junctures in making environmental rules.

Scheuer responded that Reagan's complaint was "wholly without merit" and a "smokescreen for the real target of this veto." That target, he said, was the bill's requirement that 20 percent of the funds go toward long-term research into environmental problems.

The legislation authorized a ceiling of $267 million in the current fiscal year and $282 million next year for EPA research activities. But this year Congress appropriated only $220.8 million, and Reagan has signed that appropriation into law.

Scheuer said the appropriation law does not include a 20 percent mandate specifying how the funds should be spent. Thus, if the veto were sustained, the EPA would be free from this restriction.

Also yesterday, Reagan signed legislation that will help the Asian-born children of American soldiers enter the United States and gain citizenship.

Thousands of so-called "Amerasian" children, fathered by U.S. servicemen, were left in Asia after the Korean and Vietnam wars to suffer what Reagan called "the most wretched of circumstances," often "ostracized in the land of their birth." The legislation will assist those Amerasian children born in Korea, Vietnam, Laos, Kampuchea and Thailand since 1950.

Capping another week of politically inspired presidential activity, Reagan was told yesterday that an agreement between the Small Business Administration and the Department of Housing and Urban Development will steer $5 billion into investment in small businesses in 21 states.

Reagan said it would create "thousands and thousands of new jobs," and added -- at the conclusion of a week of staged good-news events -- "This is good news."