Former vice president Walter F. Mondale, previewing his midterm campaign speech for a National Press Club audience yesterday, indicted the Reagan administration "not only for an economic program that has failed but for a profound lack of fairness and compassion."

In a wide-ranging 35-minute talk, Mondale advocated a number of specific policies that are likely to fuel debate, not just in 1982, but in his expected bid for the 1984 Democratic presidential nomination. They range from repeal of the scheduled 1983 tax cut and imposition of a refundable energy tax to the imposition of a "freeze" on nuclear weapons and a scrapping of the MX missile system and the B1 bomber.

Speaking to a receptive audience that included several dozen former officials of the Carter-Mondale administration, he also showed himself ready to defend the record of that administration and his part in it.

While acknowledging that the Democrats should have done more to spur business investment and curb regulatory paperwork when they were in power, he closed the question period to heavy applause by declaring, "For four years, we told the truth, obeyed the law and kept the peace--and that's not bad."

Mondale has by far the heaviest 1982 campaign schedule of any of the 1984 Democratic hopefuls. Aides said that recent deterioration in the national economy prompted Mondale to "get out front" on the issues nationally through yesterday's speech and last Sunday's appearance on CBS' "Face the Nation."

He lost no time in launching his attack yesterday, saying in the first minute of his speech that the Reagan administration bore full responsibility for "a recession that did not need to happen." He called the three-year, 25 percent tax cut enacted last year "one of the most bizarre" ideas in history, and said he had opposed it and its predecessors since they first appeared as Republican doctrine in 1978.

"It was obvious even to a fifth-grader," Mondale said, "that you could not massively cut taxes, sharply increase defense spending and balance the budget, all at the same time," without "pushing up real interest rates, bringing new investment and growth to a standstill."

Warning that Congress cannot change these policies unless "the president is willing to be a part of the change," Mondale called on President Reagan to withdraw "the most misleading budget ever produced."

He called for scrapping the 1983 income-tax cut, trimming business tax reductions voted last year, and delaying the income-tax indexing provision scheduled for 1984. These steps would cut the 1985 deficit by $50 billion, he said.

To pull out of the recession, Congress should advance the July 1 tax cut to April 1, he said. Defense spending should be cut $10 billion below Reagan's targeted increase. With these steps in place, Mondale said, the administration could insist that the Federal Reserve Board "ease up on the money supply, which would reduce interest rates and permit the economy to grow."

In addition to those views--widely reflected among congressional Democrats--Mondale laid down an attack on the social policies of the Reagan administration that was clearly in the tradition of his mentor, the late Hubert H. Humphrey.

He ticked off the whole litany of liberal causes: tax reform, civil rights, equal rights, human rights, the environment, education, energy conservation, nuclear disarmament, and income security.