Dissident leader Andrei Sakharov, exiled Tuesday for allegedly giving Soviet military secrets to the United States, "will not face legal charges," a senior Communist Party official said today.

Valentin Falin a member of the Central Committee apparatus, maintained that "on humanitarian grounds and in view of his former services, Sakharov will not face legal charges. He will be able to continue working in his profession."

Falin, a former Soviet ambassador to West Germany, is one of the most authoritative officials free to speak with Western correspondents.

Sakharov, 58, banished to the provincial city of Gorki that is closed to foreigners, is serving indefinite internal exile and was stripped of all state honors.

The physicist was accused in Wednesday editions of Izvestia, the government newspaper, of "blurting out" to American diplomats, agents and correspondents secrets he learned during his years at the center of the Soviet hydrogen bomb program in the 1950s and 1960s.s.

Izvestia strongly indicated that Soviet secret police might have prepared grave official charges against him.

No foreign source here tonight was willing to conjecture that Falin's assurances carried full authority in a country where Communist Party reprisals can reach into any aspect of life.

There is suspicion here that the Soviets may simply be seeking to dampen the latest international uproar until after the Moscow Olympics and then may proceed with formal charges against Sakharov.

But they pointed out that Falin's remarks, coming so soon after Sakharov was sent to Gorki with his wife, Elena Bonner, indicate the authorities acknowledge the impact of the move against Sakharov in the West, coming within a month of the Soviet invasion of Afghanistan that has brought worldwide condemnation.

Falin's remarks seemed aimed especially at West European communist and socialist parties, which have joined the chorus of criticism of the Soviets for moving to silence Sakharov, Russia's most commanding dissident figure and winner of the 1975 Novel Peace Prize for defending individual freedoms in this authoritarian state.

In an interview that appeared today in Der Stern, a prominent West German magazine, Falin was quoted as saying:

"Every state cherishes its good reputation and takes care of its security You surely know in what area Academy of Science member Sakharov worked and it is precisely in this field that some people take an interest in the West. Just recently, Sakharov's Western contacts have been asking a lot of questions on this subject, which has nothing to do with ideology."

Falin's assistant, Vitali Kobysh, repeated for Moscow correspondents the official's assurance that no legal action would be taken against Sakharov. Falin told reporters he was "too busy" to speak with them.

In assessing the Soviet banishment of Sakharov, foreign observers now believe the Kremlin ordered it in a specific retaliation against President Carter. His invasion reprisals, including a partial grain embargo and a threat to boycott the summer Moscow Olympics, seem to have surprised and angered the Politburo and Soviet President Leonid Brezhnev.

These sources believe this is the only plausible explanation for the authorities' decision to move against Sakharov so close on the heels of the Afghan invasion.

"The Russians could easily have waited until July 18 or 19," when the Olympics are to open here, "to take Sakharov," one source said in a characteristic comment. "The world could hardly have responded with an effective boycott. Doing it now shows the personal pique Brezhnev must feel toward Carter."

Early in his administration, Carter sent a personal letter of support to Sakharov. Although the White House has sharply moderated presidential human rights rhetoric, outrage continued against what was termed "meddling in Soviet internal affairs."

The official Soviet news agency Tass struck a jeering tone in its first comment on the Sakharov affair. "Sakharov has not been exiled," asserted Tass. "He has been moved beyond the bounds of the city of Moscow . . . resettled in Gorki, one of the most beautiful cities of Russia."

In a Moscow commentary, the agency said Westerners who criticized the move were "crybabies," and said the White House, using information from "dubious sources, hastened to express its regrets and outrage without giving itself the trouble of verifying the actual measures taken with regard to Sakharov."

It said the move was comparable to moving from Washington to Philadelphia, Baltimore, Boston, "or at worst, Detroit or Cleveland. It should be remembered that Soviet citizens working in the U.S. cannot go to any of these cities without a special permit."

Tass said the West was angered that Sakharov is now in a closed city -- Gorki is off-limits to foreigners because of an aircraft factory there -- "not by their concern or pity for Sakharov. They are mad at no longer being able to cite him as a source of slanderous 'information' about the Soviet Union and its policy."

Tass repeated the Falin statement that Sakharov would not face "court proceedings" despite the fact that the "slandered and renegade embarked upon open libel of the Soviet state and people, which itself is a punishable criminal offense." It claimed the United States had similar laws.

Meanwhile, Sakharov family sources reported that his mother-in-law, Ruth Bonner, and close family friend, Lisa Alexeyeva, are headed for Gorki with "books, materials, vegetables and fruit" for the exiled couple.

As a provincial city, Gorki stands far below Moscow in supply of foodstuffs. Mrs. Bonner's daughter, Sakharov's second wife, is not formally under the "administrative ban" against her husband and may travel to Moscow, it is understood.