The Soviet Union responded tonight to the expulsion of 55 Soviet diplomats from the United States by expelling another five American diplomats and barring 260 current Soviet employes from working at the U.S. Embassy here and at the U.S. Consulate in Leningrad.

Soviet leader Mikhail Gorbachev, in an hour-long television speech tonight, blasted the expulsions by Washington as "simply wild in the normal human view," coming a week after the Reykjavik summit meeting.

"We do not intend to allow such outrages," he said, delivering a particularly harsh verdict on the Reagan administration's interpretation of the Reykjavik meeting.

[The withdrawal of the Soviet support workers at the American embassy will cause immediate, major disruptions in the embassy's ability to function, senior State Department officials said privately in Washington. Story on Page A34.]

A somber, almost bitter Gorbachev complained that the Reagan administration had "distorted" the events at Reykjavik, was engaging in "petty politicking" and had staged the expulsions as a "provocation."

"It does not even have a desire to maintain the atmosphere which is essential for a normal continuation of the dialogue," he said.

"What kind of government is it and what can be expected from it in other areas of international relations?" he asked. "How far will its unpredictability go?"

Gorbachev repeated, however, that the Soviet arms control package presented in Reykjavik still stands -- signaling that despite the recent spate of angry bilateral exchanges, Moscow will press for its nuclear disarmament proposals.

"The Reykjavik meeting greatly facilitated, probably for the first time in many decades, our search for disarmament," Gorbachev said, adding that the debate on arms control had reached a "higher level." But Gorbachev complained that "there is no keeping the 'hawks' in the White House in check."

"It took only several days . . . for everything that was spoken of in Reykjavik to begin to plunge into the fog of inventions and fantasies," he said.

For instance, Gorbachev insisted that President Reagan "did, albeit without special enthusiasm, consent to the elimination of all . . . all, not only certain individual, strategic offensive arms, to be destroyed precisely over 10 years, in two stages."

He also criticized growing concern in the West about the superiority of Soviet Bloc conventional military forces if U.S. and Soviet intermediate missiles are removed.

"Certain voices in Western Europe even maintain that it is difficult to part with the American nuclear weapons, with the American missiles," he said.

The Soviets' expulsion countermeasures, detailed tonight by Foreign Ministry spokesman Gennadi Gerasimov, seemed aimed at duplicating in Moscow the exact results of the expulsions from Washington. In both cases, the ceiling on diplomatic personnel is being held to 251.

The Soviet order could cripple the U.S. Embassy by requiring diplomats to drive themselves, do routine paperwork and other functions required to run a large embassy.

An embassy spokesman said tonight that it was unclear how the mission would function without its Soviet employes. "If they show up tomorrow, they will have work to do. If they don't, we will have to get along without them. It is still a little early to say what the impact is," said press attache Jaroslav Verner.

The State Department said yesterday that it was expelling five Soviet diplomats -- four from the embassy in Washington and one from the consulate in San Francisco -- in direct retaliation for Sunday's Soviet announcement that five American diplomats had been declared persona non grata here for "impermissible activities," often a euphemism for spying.

Washington also said it would expel another 50 Soviet diplomats -- 38 from Washington and 12 from San Francisco -- to bring overall staffing to the same level as American diplomatic representation in the Soviet Union.

Both Soviets and Americans agree that the level of American diplomats in Moscow is 225 and the number at the consulate in Leningrad is 26. Both sides also agree that Soviet staffs in Washington and San Francisco are much larger, totaling more than 300.

The disproportion in staff size is largely due to Soviet insistence on importing all of its embassy personnel, and its refusal to hire any American staffers.

In contrast, the two American diplomatic missions in the Soviet Union employ about 260 Soviet citizens, including drivers, maids, clerks, receptionists and other office staff.

The Soviet staffs here have long been a controversial subject, particularly on Capitol Hill, where politicians have complained that they pose a significant security risk.

Soviets working for foreigners are in fact employes of a branch of the Soviet Foreign Ministry, which has ultimate control over hiring and firing. Because of security concerns, Soviet employes have long been barred from many key embassy offices.

In recent months, the U.S. Embassy has been gradually reducing its Soviet employes, although some are considered essential because of their language and knowledge of the city and its bureaucracies.

Gerasimov said tonight that to keep a tight ceiling on American embassy personnel, the Soviet Union will strictly limit the entry of Americans on temporary assignment to the embassy. He said 500 such people have been rotated into Moscow and Leningrad in one year.

Gerasimov also said that the American embassy in the future would be barred from hiring employes from third countries.

Another restriction will sharply control the number of personal guests invited to Moscow by U.S. Ambassador Arthur Hartman and the embassy.

Gerasimov said Hartman had 63 guests in the past year, and that 130 more people had come as guests of the embassy. In the same period, the Soviet ambassador in Washington had no personal guests, he said. If "balance" is to be the main principle, Gerasimov said, "then we can have it in these trifles as well."

The ousted U.S. diplomats, who must leave before Nov. 1, are Naval Attache Thomas Holme, Military Attache Richard Naab, Second Secretary Michael Morgan, Third Secrtary Michael Matera and Leningrad Vice Consul Daniel Grossman. All five were accused of "impermissible activities against the Soviet Union."

Gerasimov indicated today that if the United States retaliates again, the Soviet Union is prepared to match its actions.

He also gave the first public acknowledgement that the expulsions of five American diplomats announced Sunday were in reaction to the expulsions of 25 members of the Soviet U.N. mission. "It was a minor response," said Gerasimov, "not a complete response. But instead of that, the U.S. administration chose the road of escalation."