President Reagan yesterday accused the Soviet Union of using military power to extend its influence to "every corner of the globe," and hailed a new government booklet on the Soviet buildup to bolster the case for his defense budget.

Reagan's statement was part of a public relations offensive launched yesterday to convince the people and Congress that it would be unsafe to cut the proposed $274 billion Pentagon budget substantially.

The Soviet Union, he said, is "the only nation with the military power to inflict mortal damage directly on the United States." The new booklet, he added, will let the American people "compare Soviet forces with our own."

Defense Secretary Caspar W. Weinberger underscored the president's remarks, telling a Pentagon news conference that the Soviets were bent on "world domination." In a similar vein, Vice President Bush told the American Business Conference, which supports defense cuts, that such action would "have the Soviets win in the Congress that which they failed to win in the German election," which victorious Chancellor Helmut Kohl has called a mandate for deployment of new U.S. nuclear weapons.

Democrats promptly denounced the Pentagon study. Sen. Edward M. Kennedy (Mass.) called it "classic scaremongering." Sen. Gary Hart (Colo.), a presidential candidate, said the report "makes it sound as if the Russians are just over the horizon."

A 107-page booklet called "Soviet Military Power" and prepared by the Defense Intelligence Agency was released for publication at the opening of the news conference.

The booklet details Soviet nuclear and conventional forces, but makes no startling disclosures. It documents that the Soviets are pursuing many weapons that the United States already has deployed, as well some that the Pentagon abandoned years ago.

A government official involved in the DIA report told reporters in a Pentagon briefing Tuesday that after sifting through the information he did not believe the Soviets held "the edge" over the the United States in strategic weapons, meaning those for all-out nuclear war such as missiles and bombers. "Strategically we are better," he said.

His not-for-attribution comment caused tittering among reporters and consternation among Pentagon officials. Yesterday, in a "supplementary" not-for-attribution statement, the senior official said, "I meant the United States has an edge in the largest sense--society compared to society." He added that he agreed with Weinberger's statement that "the Soviets have acquired a margin of nuclear superiority in most important categories.

The DIA's report--300,000 of which are to be printed by the Government Printing Office and sold to individuals here and abroad for $6.50--is an update of a similar, slick-paper report released by the Pentagon in September, 1981.

Weinberger has been beleaguered by critics who contend Reagan's fiscal 1984 defense request of $274.1 billion in spending authority and $238.6 billion in outlays is excessive given looming federal deficits of $200 billion or more. To answer them, he pushed the intelligence community to release previously secret information on Soviet weaponry and forces.

The DIA not only described Soviet weapons and their capabilities with the help of artist's renderings, photographs and charts, but also discussed new trends in Soviet military strategy.

The DIA said the Soviets are moving aggressively to seize the military initiative in outer space and, for ground warfare, are opting for the same kind of hard-hitting, highly mobile, deep penetrating outfits that the U.S. Army is favoring as it designs its future forces.

The Soviets in trying to seize the high ground of outer space are pushing ahead with anti-satellite weapons, with a space plane, which the Air Force pursued and abandoned more than two decades ago, and with laser beams that could destroy objects and kill soldiers.

The lasers, according to the DIA report, might be put aboard Soviet satellites by the Soviets to destroy enemy satellites or missiles in space. The intelligence agency added that the Soviets are experimenting with lasers for land warfare, predicting that "in the mid-1980s" they may have one powerful enough to kill enemy soldiers.

The report documents the fact that the Soviets have been and are continuing to copy U.S. weapons, even some found wanting by the Pentagon. Examples from the report:

* Mobile intercontinental missile. The Soviets are developing two solid fuel intercontinental ballistic missiles, one "about the size of the U.S. MX intended for silo deployment; the other is a smaller missile, which will probably be designed for deployment on mobile launchers." The Reagan administration is following the same two tracks, with a small mobile missile gaining adherents.

* Cruise missiles. The Soviets are following the U.S. lead and building a family of cruise missiles to be launched from airplanes, ships and submarines.

* Long-range bombers. The Soviets are developing a new bomber called Blackjack, which like the American B1B has wings that swing back and forth.

* Jumbo transport. "The Soviets are developing a new long-range heavy lift transport comparable to the U.S. C5A" already deployed by the U.S. Air Force.

* Nuclear aircraft carrier. "The Soviets soon will begin construction of a large, nuclear-powered aircraft carrier" which, like the Nimitz, will carry first-line fighter planes. The Soviet Kiev carriers already at sea are limited to carrying planes that can take off on a short stretch of deck rather than be catapulted.

* Missile submarines. The Soviets are building Typhoon submarines which can carry 20 missiles as their answer to the U.S. Trident submarine.