American intelligence analysts say a burst of Soviet missile test firings last week follows closely the sequence of events that would unfold during a nuclear war, with the first shot meant to knock out U.S. intelligence-gathering satellites.

Secretary of State Alexander M. Haig Jr. disclosed the series of Soviet tests in an unusual news conference statement in New York Saturday. Haig claimed the strategic weapons tests were "integrated" and "unprecedented in their scope."

Although the Soviets have conducted tests of their missile arsenal before, experienced analysts here say such tests are rare. What really "dazzled" U.S. experts this time, as one source put it, was the inclusion of the antisatellite tests, probably for the first time, into a large-scale exercise.

The exercise followed the initial antisatellite shot with rapid firings of other land- and submarine-based missiles and then defensive missiles.

Sources said the Soviets have probably held about six of the large-scale test exercises over the last 15 years in which they go through the sequence of events that could unfold in a nuclear war, but that none of these previous episodes was as extensive as this one.

Defense Secretary Caspar W. Weinberger, asked yesterday on "This Week with David Brinkley" (ABC, WJLA) if he agreed with the assessment that the tests "looked like a scenario for fighting a nuclear war," replied: "Yes, I agree . . . .

"This is just another piece of evidence displaying the fact that they believe that a nuclear war can be fought and can be won."

Weinberger suggested that the Soviets might have intended the tests to "send out a signal," but other sources suggested that such exercises are probably not meant to impress Americans, who can observe them using satellite technology. Rather, they said, the tests are more likely meant to demonstrate to the Soviet hierarchy whether their systems work, at least in carefully planned exercises.

Haig said the exercise included tests of an antisatellite weapon, two test launchings of land-based intercontinental-range missiles, one launching from a missile submarine, one launching of a land-based intermediate-range missile and two launchings of antiballistic missiles meant to shoot down incoming enemy missiles.

Haig volunteered no further details or assessments, and he did not accuse the Soviets of violating any previous arms control agreement. Rather, he appeared to want to use this normally highly classified information to counter any public perceptions that Moscow was more intent on arms control than Washington and to counter any public relations gains the Soviet Union may have made at the United Nations disarmament conference last week.

Soviet Foreign Minister Andrei A. Gromyko had relayed to the United Nations last Tuesday a pledge by Soviet President Leonid I. Brezhnev that Moscow would not be the first to use atomic weapons in any conflict.

"Such activity," Haig said of the Soviet tests, "belies by specific actions the words put forth to the world audience here this week."

Haig's news conference statement Saturday came after two days of private meetings with Gromyko in New York, but Haig said he did not bring up the missile tests in the private meetings because much of the information was still being analyzed. Sources here say the Soviet test firings, which did not involve any totally new weapons, took place within "a very few hours" last Thursday or Friday.

The first shot was the antisatellite weapon, which normally would be used to knock out American reconnaissance satellites trying to spot and warn against Soviet attack.

Then came what specialists call a "ripple firing" of land- and submarine-based missiles. A ripple firing normally means firing more than one missile in rapid succession, aimed at dealing a knockout blow to American land-based missiles or other military targets.

This was followed quickly by launching of the antimissile missiles, simulating the attempt by Soviet defenses to shoot down any American missiles that survived an initial attack and were trying to counterattack against targets in the Soviet Union.

Sources say the Soviets tend to have these full-blown exercises every two to four years, but usually the antisatellite tests are separate.

Normally, specialists say, the satellite to be used as a target is fired into space and the antisatellite weapon is fired at it several days later. This time the Soviets apparently fired at the target satellite soon after it was launched, on its first or second orbit, and quickly followed up with the rest of the offensive and defensive tests.

Because of the extent of these exercises, they are normally planned far in advance, U.S. experts believe, and are normally held in June or July when the weather is reasonably good.

Thus, some analysts do not believe that the current tests were meant to be any specific signal to Washington growing out of recent events, such as the U.N. disarmament conference or the fighting in the Middle East or South Atlantic.

The United States also conducts occasional test launchings of both land- and submarine-based missiles, but does not have an antisatellite weapon or an antiballistic missile in service.