CONGRESS WILL have to act boldly in the coming year if the federal budget--and the national economy--are to be put on a sensible course. In last Wednesday's press conference, President Reagan may have been indicating some willingness to compromise--or he may simply have been sidestepping budget questions. But it appears unlikely that he is ready to provide strong leadership on the tough issues that need resolution this year--Social Security, the defense budget and taxes. Will Congress be able to do the job largely on its own?

The Democratic leadership in the House got off to a somewhat rocky start, pushing through several rules changes that will tighten leadership control over legislation. That irritated moderate Republicans, whose help will be needed. But the House needs stronger leadership than it has had recently. The fact that Speaker Thomas P. O'Neill could not deliver a working majority on most issues actually increased difficulties for the Senate Republican leadership on issues, such as Social Security, where a compromise is essential.

In the Senate, the same leaders who pushed through major legislation last year seem ready and able to outdo their past performances. Majority Leader Howard Baker, whose pragmatic leadership kept Congress from stalemate last year, is determined to reassert the control that was threatened by the lame-duck, right-wing rebellion.

Finance Committee Chairman Robert Dole-- who fashioned last year's tax and voting rights compromises--has apparently decided that he will take on the job of working out a Social Security compromise. Sen. Dole had been hanging back, hoping that the White House would provide the impetus for its bipartisan commission to spell out a compromise. Now that it's amply clear that the president is still gun-shy, Sen. Dole has been engaging in shuttle diplomacy for the last few days, trying to broker a deal between the White House and Democratic leaders.

On the budget front, Sen. Pete Domenici's Budget Committee is fully primed to provide an alternative budget strategy if the president's budget proposals fall as flat as they did last year. As the result of extensive briefing and deliberations over the last two years, most senators now understand budget choices very well--perhaps better than most administration officials.

Both Senate and House leaders will have a tough time getting their defense committees to review Pentagon spending thoroughly and weed out those programs that don't add enough to national security to justify their future costs. But pressure will be added by leadership determination that this year the budget process won't fall behind schedule as the result of haggling with the administration.

This is a heavy load for a legislative body in which discipline and statesmanship have frequently been in short supply. But Congress now has strong leaders and a sense of urgency that may do the trick.