President-elect Jimmy Carter will support a simple one-year extension of most major domestic programs expiring this year and concentrate his first-year legislative program on a half-dozen major fields, his top domestic policy assistant said yesterday.

Stuart Eizenstat, Carter's issues coordinator during the campaign and transition, said the new President's top priorities will be the passage of his economic stimulus package, creation of a Cabinet-level energy department and enactment of a national energy policy, and acquisition of executive authority to reorganize government agencies.

But Eizenstat, who is expected to be named this week as the assistant to the President for domestic policy, said Carter would attempt to put his imprint on laws in areas ranging from wildlife habitats to health care costs, housing subsidies, lobby and campaign finance reform, wiretaps, air fares and law-enforcement grants.

The 33-year-old Atlanta attorney said Carter had cleared a 100-page draft of the 1977 legislative program at a meeting in Plains last Thursday. The draft is now being circulated among Cabinet members for their suggestions, Eizenstat said.

Among the deadlines Carter has tentatively set are these:

By Feb. 3, legislation to create a Department of Energy, combining scattered energy functions, should be ready to go to Congress.

Legislation restoring the President's right to make internal reorganizations in federal agencies, subject to 60-day veto by either house of Congress, is also to be ready by Feb. 3.

Eizenstat said the legislation will give Carter that authority for a full four years and allow him to amend his own reorganization plans within the first 30 days they are before Congress.

By April 20, he hopes to have drafted companion messages outlining national policies on energy and the environment. The environmental package will include recommendations on strip-mine legislation, the outer continental shelf, oil spillage problems and the improvement of wildlife habitats.

By May 1, Carter expects to have draft legislation for a welfare reform plan from Joseph A. Califano Jr., designated Secretary of Health, Education and Welfare. However, Eizenstat said, the timing of congressional action in that area has yet to be determined.

All this is in addition to the economic stimulus package of tax cuts, public service jobs and public works, which Carter negotiated with Democratic congressional leaders last Friday and is now preparing for formal submission.

Eizenstat said the incoming President was under severe "constraints of time" in meeting the deadlines imposed by the new congressional budget procedures.

"We don't even know what the Ford budget will look like," he said, "and we are required to have our amendments to it prepared by March 1 at the latest."

Eizenstat said he believes the outgoing President in the budget he submits next Monday will propose "across-the-board" cuts in domestic programs, requiring Carter to seek substantial additional funds just to maintain programs at the "current-service levels."

On the other hand, he said, he expects Ford to hold down Pentagon budget increases to the point that it will be "hard" for Carter to achieve the promised $5 billion reduction.

The other problem facing the incoming administration, Eizenstat said, is that "more domestic legislation is expiring this year than in any of the last five years."

Among the laws that face renewal, expiration or change are basic measures for air and water pollution control, energy research, employment programs, health services, housing and farm programs.

Eizenstat said Carter has advised congressional leaders that his administration cannot review all of the laws in time to recommend changes this year, "so we'll have to seek a one-year extension at an agreed-upon level of funding in many cases."

In some instances where the administration will not have recommendations of its own to make, "we'll be quite content to let Congress take the initiative and just comment on the changes they initiate."

But there are a number of areas where Carter himself will be making proposals, and Eizenstat gave the most detailed preview of them yet offered.

Electoral reform - Carter thinks legislation binding electors to vote for the person winning a popular plurality in their state "certainly should" be passed. Support of a constitutional amendment to eliminate the electoral college and provide for direct election of the President "is under study, but it's a very tough issue."

Ethics and political reform - Carter will seek legislation to authorize use of a court-appointed special prosecutor to investigate certain categories of official crime and scandal, but the guidelines have not yet been specified.

He will also introduce legislation to carry out his financial disclosure requirements for policy level executive appointees; support lobby legislation requiring federal officials to maintain a public log of their contacts with lobbyists; support public financing of congressional elections and some mechanism for "universal voter registration."

Farm - Carter's preference is for a one-year extension of expiring basic farm legislation, but it Congress prefers a four-year extension, the administration will draft recommendations for any changes it seeks.

Health - Key legislators have agreed to one-year extensions of expiring programs for family planning, migrant health care, community mental health centers and neighborhood health clinics.

The major new initiative will be in the area of "cost-containment," based on a broadened application of legislation introduced by Sen. Herman E. Talmadge (D.-Ga.) to provide incentives for hospitals that keep down patient-care costs. Eizenstat said Carter will also back tougher penalties for Medicaid fraud and abuse, saying that cost control "is an essential predicate for national health insurance. Unless you can control costs, there's no point in going forward with national health insurance."

Housing - The focus will be on "rejuvenation" of the Section 8 rent-supplement, Section 235 home-owners' subsidy and Section 312 rehabilitation loan programs. Eizenstat said proposals to tailor the programs to be of even greater advantage to city-dwellers are being developed.

Justice - Two proposals have priority. One is a wiretap bill to require judicial approval of all or virtually all domestic wiretaps, with standards specified for the categories of cases where they will be allowed.

The second is a redirection of LEAA (Law Enforcement Assistance Administration) funds of finance improvements in the courts, "rather than fancy bulletproof vests."

Regulatory reform - Carter will support, as a first step. Sen. Howard W. Cannon's (D.-Nev.) bill to change airline to markets and competition on ticket prices, rather than limiting competition to fringe benefits.

He is also considering moves to simplify government regulations by requiring the author of the regulations to sign them personally and ordering Cabinet and agency heads to cerify that they have personally read and approved regulations issued by their departments.

Tax reform - Carter has set a December, 1977, deadline for the drafting of comprehensive tax reform proposals, for submission to Congress in 1978.

Urban program - In addition to the increase in public-service and youth jobs programs and counter-cyclical aid contained in the economic stimulus package, Carter is considering several other moves to aid the ctities.

He wants to change the distribution formulas on community development and public works grants, both of which expire this year, "for better targeting to areas of need."

There will also be "some mechanism" to help New York City handle its debt problems, and it may be designed in a way that will make it available for other cities "in real emergencies," Eizenstat said.

Eizenstat also disclosed that Carter has set a target of a 30 per cent cutback in the political appointees on the White House staff, roughly from 235 at present to 170. He said that would reduce the staff of the Domestic Council from 40 to 28 people.