IN HIS public pronouncements of the past few days, President Reagan has reaffirmed his belief in the danger of big federal deficits. He has also made it quite clear that, after almost 2 1/2 years in office, he accepts no responsibility for the record- breaking deficits the country now faces. This position is, at best, disingenuous.

On Monday, the president depicted deficit spending as "one of the most alarming dangers to our republic." The cause of those deficits? Why, nothing besides "uncontrolled spending and . . . addiction to big government." Since the president is himself the major proponent of vast increases in defense spending, it is clearly domestic spending that he finds out of control. And who is to blame for that? Why, no one but Congress.

In the opening statement of his press conference Tuesday, the president asserted that if the "hard- won recovery" is reversed, it will be the fault of the budget committees because they rejected his "common-sense budget." But all of the budget resolutions being debated by Congress would produce lower deficits than the president's budget. What he doesn't like about them is that they achieve that result by slowing the rapid increase in defense buying and by scaling back his tax reductions.

It is true that none of the resolutions gives the president the net savings in domestic spending he wants--and the House-passed resolution calls for substantial increases. But there are good reasons for congressional reluctance to cut back more on environmental enforcement and abatement efforts, welfare benefits for the nation's poorest families, child nutrition and emergency jobs.

Still, what if Congress threw caution to the winds and accepted all the president's requested domestic changes--including a big increase in politically popular water projects? In the face of a projected deficit topping $200 billion, the president asked for net domestic savings of about $17 billion next year. Not inconsequential, but hardly enough to save the republic from being washed away in a sea of red ink.

The president did recognize that something other than Congress--specifically, the deep recession-- has contributed to the massive deficits now being piled up. But to him the recession was simply "falling off the cliff"--an unfortunate occurrence unconnected to any of his own policies and unforeseen by "all the economic advisers there are." This will surprise the host of conventional economists who warned that the administration's peculiar combination of tight money and loose fiscal policy would produce exactly what occurred--a deep recession.

Having talked Congress into a woefully incompatible set of defense and taxing policies, the president now denies that he is in any way to blame for the consequences. That's not a pleasant situation for Congress, which must now take on the unfair but necessary burden of putting the Treasury back on a sound fiscal basis.