Despite a strenuous fight by Secretary of State Alexander M. Haig Jr., the Reagan administration's proposals on nonmilitary foreign aid in fiscal 1982 represent a drastic cutback of U.S. economic development asistance.

The plan made public yesterday describes expenditures of $5.392 billion -- a 26 percent cut from former president Carter's proposed budget.

Although the State Department last night described the proposal as "a good result" that will not impair the effectiveness of the foreign aid program, it clearly represented a victory for budget director David A. Stockman over State officials who had hoped to prevent such deep cuts.

Sources at State, while conceding that the cuts were "more than a flesh wound" and closer to Stockman's ideas than their, said the figures unveiled yesterday were presented in a way that made them appear even larger than they are.

That, these officials said, was because of a mutual agreement to separate from the foreign aid dispute almost $800 million one special category of aid -- a figure that will be covered elsewhere in the budget and that actually brings the amount being asked for economic assistance to slightly more than $6 billion.

In addition, the sources continued, other reductions were achieved in the fiscal 1982 proposal by deferring certain obligations to later years, principally in the form of U.S. pledges to multilateral lending institutions.

These maneuvers appeared to be a mutual face-saving way of papering over some of the differences that surfaced three weeks ago with leaks to the press of an Office of Management and Budget memo calling for the most drastic cuts in the history of the foreign aid program.

Yesterday's description of the foreign and proposed made clear that Stockman succeeded in getting cuts in every aspect of nonmilitary aid.

In the original memo Stockman, focusing on Carter's proposal to increase nonmilitary aid from $6 million to $8 million in fiscal 1982, called for trimming that to $5.4 billion -- a figure that he apparently achieved.

However, the sources noted, the figures presented yesterday worked from a 1982 base budget authority figure of $7.246 billion, which represents the Carter proposal minus all military assistance. That includes $796 million for the Economic Support Fund, used to aid countries where the United States has vital security interests.

In the dispute between State and OMB this originally had been counted as economic assistance. Since it will be retained under another category, it actually raises the economic aid proposal to more than $6 million.

Under another compromise, the sources said, a dispute over a three-year commitment of $3.24 billion to the International Development Association will be handled in a way that reduces the 1982 figure. Instead of being paid in three equal installments, as Carter had proposed, the commitment will be met with a small payment the first year, a slightly larger one in the second year and a much larger one in the third year.

Finally, these sources said, further savings will be made by stretching out over a longer period the payments of U.S. commitments to other international institutions.