Defense Secretary Harold Brown has roused admirals to battle stations be telling them to tailor future Navy forces for "localized contingencies" rather than a big war in Europe.

Navy leaders fear Brown's recently issued secret guidance paper, which The Washington Post has obtained, will downgrade their service and jeopardize the future of highly prized aircraft carriers.

Brown's Navy guidance paper is certain to reopen the congressional debate over carriers, with this week's hearings by the House Armed Services Committee the likely starting point.

Brown makes these points in his secret paper designed to guide Navy leaders as they plan for the years 1980 through 1984:

The 12 Navy aircraft carriers now deployed and their 180 to 240 escort and support ships represent an investment of $100 billion to $120 billion. "Carriers, more than any other force element, determine the size and cost of the Navy."

It would be less expensive to rely on land-based rather than carrier planes to control the Mediterranean on the southern flank of NATO.

Using carriers to defend the North Atlantic against Soviet Backfire bombers would "unfortunately" make "the carriers themselves prime targets for the Backfires."

Land planes based in England, Iceland, the Azores and Greenland could provide "the same or better protection" against Backfires at less cost than carriers.

Reducing the number of carrier task forces from 12 to 10 would save $1.2 billion a year in operating costs and $16 billion to $20 billion in future construction costs.

Citing the cost of carriers and their vulnerability to Soviet forces in a European war, Brown gave Navy leaders this guidance:

"The Navy should plan carriers, surface combatants, direct support submarines, underway replenishment groups and amphibious forces for localized contingencies outside of Eucess.)

"No new carriers should be bought until the feasibility has been decided" of finding a home port for them in Europe, rather than rotating carriers between East Coast ports and the Mediterranean. (The Navy has explored this option before, with no success.

Brown's guidance was contained in Section L of a thick package of papers sent to all the service chiefs. They have been asked for comments, to form the basis of possible amendments.

Some of Brown's guidance to the Navy conflicts with the thinking of not only many admirals but top civilian leaders.

Navy Secretary W. Graham Claytor and Undersecretary James Woolsey, for example, have unsuccessfully been pressing Brown to cancel the Northrop F-18 fighter plane now under development and to spent more money on planes that can take off and land vertically - V/STOL aircraft.

But Brown, in one of his guidance papers now circulating in the Pentagon, flatly rejects that advice.

"The Department of the Navy is to continue" to build fighter and attack versions of the F-18, Brown states. "The F-18 will equip six of the Navy's 24 active fighter squadrons and all Marine fighter squadrons."

As for the AV-8B Harrier V/STOL fighter the Marines want to buy in quantity, Brown said that only if tests show it to be "actually superior in cost-effectiveness to the A-18" will he "consider producing it for Marine light attack squadrons."

House Speaker Thomas P. O'Neill Jr. (D-Mass.) has been highly protective of the F-18; its engines are built in the General Electric plant in Lynn, Mass.

Brown has summarized his overall military strategy and guidance in a document The Washington Post quoted on Thursday. On Friday White House press secretary Jody Powell told reporters in reference to The Post's article that "you are dealing with a draft of a section from a planning document."