Defense Secretary Caspar W. Weinberger has ordered the military services to prepare what one official termed "a detailed, reverse wish list" of programs that would be delayed, forces cut and purchases stretched out if President Reagan's $1.6 trillion five-year defense plan is cut.

Yesterday, the Defense Resources Board, a high-level Pentagon budget committee, met to review the services' lists and compile one list to serve as a guide in any presidential budget decision, according to Pentagon sources.

The Air Force, for example, reportedly said that if a cut of more than $3 billion were made in its planned fiscal 1983 budget, it would have to phase out old B52D bombers and close two Strategic Air Command bases.

At the highest reduction level, about $12 billion in one year, the Air Force might have to begin phasing out its old Titan II intercontinental missiles because of the high cost of maintenance.

A Pentagon official termed the combined list "an impact statement, to give the president an idea of how hard real capability could be hurt depending on how deep a cut is made."

Sources on Capitol Hill and in industry see the exercise as another sign that cuts will be made in defense and other agencies but that a struggle is continuing between Weinberger and David A. Stockman, director of the Office of Management and Budget, about the size of those cuts.

Weinberger and Stockman met inconclusively for five hours last Wednesday in California with White House counselor Edwin Meese III to discuss possible cuts in defense spending.

Stockman is looking for reductions in the fiscal 1982 budget, which is now before Congress, and in fiscal 1983 spending, which is in the final stages of preparation in the Pentagon.

Weinberger has been arguing against any substantial reduction in the five-year plan and said last Friday that no "substantial" reductions are contemplated.

Reagan, according to a defense official, "has indicated to Weinberger that he does not see any cuts in the fiscal 1982 numbers above a marginal level."

If defense spending for next year is not reduced to help in Stockman's current effort to slash government spending, even larger amounts may have to be cut from military programs being planned for fiscal 1983 and beyond.

Pentagon officials refused to comment about the current budgeting process, and press spokesmen said yesterday that they could offer no details.

It was learned, however, that the Air Force, for example, was told to prepare four plans -- for programs that would be affected by cuts in fiscal 1983 of $1.5 billion, $3.5 billion, $7 billion or $12 billion.

The cut levels given the Navy were "a bit higher," one source said, because its budget is higher than that of the Air Force, while Army figures were slightly lower.

The Air Force's response contained some across-the-board reductions in many programs, "cutting planned force levels and buying less munitions, putting less money in military construction and family housing programs," according to one source.

Purchase of tactical aircraft such as the F16 would be slowed, the source said.

Weinberger's original guidance on priorities for programs to be increased in the five-year plan was turned upside down and used in determining the "reverse wish list," sources said.

Since Weinberger's first objective was strategic system development to redress the so-called military imbalance with the Soviet Union, those programs were least affected in the budget-cutting exercise, sources said.

On the other hand, since upgrading force structure by increasing the number of personnel and equipment was the lowest of Weinberger's priorities, those programs were looked at hardest for cuts, they said.

In that process, sources said, it was expected that the Navy might take the biggest reductions.