President Carter completed basic work yesterday on a $532 billion budget for fiscal 1980 that aides say will provide $2 billion more than previously planned for job-creation and social programs but still will hold the deficit below $30 billion.

The president made his decisions during a 3 1/2-hour meeting with Vice President Mondale and top aides before leaving for a Christmas trip to his home in Plains, Ga. The White House said he plans no further meetings on spending issues before the budget comes out in January.

Officials said the only portion of the budget not fully nailed down is defense spending. Carter essentially has decided to let military outlays rise by almost the full three percent, after inflation, that the promised foreign leaders-a spending total of just below $123 billion. But planners still must work out a few details.

Carter's decision to "restore" $2 billion in social-program cuts that his budget-markers had recommended earlier marked a compromise for the administration. Carter had been besieged by liberals, blacks, urban leaders and consumer groups protesting his budget planners' earlier proposals.

However, analysts noted the decision meant the administration had to make even deeper cuts than planned in other programs in order to restore the $2 billion in social programs and still hold the deficit below $30 billion. The actual deficit is estimated at just over $29 billion.

The $532 billion spending total Carter approved yesterday is about $16 billion below the level needed to keep existing programs intact after allowing for inflation. That means the president has decided to cut actual services significantly.

One official familiar with yesterday's meeting said planners had "squeezed every nickel the could" out of the fiscal 1980 budget.Besides Mondale, those present at the early morning session included budget di rector James T. Mcintyre and domestic adviser Stuart E. Eizenstat.

The total for defense spending includes $1 billion worth of offsetting "efficiencies" - budget-markers' jargon for savings resulting from streamlining a consolidation of military programs. Nevertheless, while officials boasted that "the Pentagon won't get all it wanted," the cuts were only token.

The $2 billion Carter "restored" yesterday was split almost evenly between public-service job slots under the Comprehensive Employment and Training Act (CETA) and a variety of health, education and urban aid programs. Carter also allowed extra funds for youth employment programs.

The extra$1 billion for CETA is expected to boost the number of public service jobs the government will be financing in the next fiscal year to just under 550,000-far higher than the 260,000-job level Carter's budget planners had proposed, but still down from this year's 625,000.

There were no immediate indications which programs Carter had restored in the health, education and urban aid areas. However, aides said one agency which had some funds "restored" was the National Institutes of Health. Another restoration was in aid for medical education.

At the same time, however, Carter ended up cutting more than his budget-makers recommended from his energy budget, slashing it to just above $7 billion, compared to $8.5 billion urged by the Office of Management and Budget and $10 billion sought by the Energy Department.

The major cuts include $1.3 billion for strategic reserves, $700 million from the department's coal research and development program and other reductions in nuclear research. The department's solar energy program was said to have been left relatively intact.

The fiscal 1980 budget, which covers the year beginning next Oct. 1, is expected to be sent to Congress on Jan. 22. Carter has pledgeto hold the deficit below the $30 billion mark as an anti-inflation tool.

The initial OMB recommendations sent shivers through the hearts of traditional Democratic Party constituent groups, which feared major slashes in longtime social programs. The fight over the CETA program was among the most controversial.