MOSCOW (AP) _ Thousands of Soviets are streaming to the United States to settle or visit relatives who emigrated in the 1970s, creating an 11-hour workday for officials at the U.S. Consulate and opening up new channels of contact between the superpowers.

The increase in the number of Soviets going to the United States is part of an overall shift in Kremlin emigration policies in the months leading up to this week's U.S.-Soviet summit meeting. Thousands of Jews, ethnic Germans, Armenians and others have left permanently or for visits to the West this year.

Jewish emigration, a hot political issue in the West, is nowhere near the peak reached in 1979, when more than 51,000 Soviet Jews left for Israel or other Western nations.

However, emigration and private trips are up sharply from 1986, when only 914 Jews and 698 ethnic Germans emigrated all year and only 500 Soviets, most of them officials, made it to the United States each month.

At the U.S. Embassy, the boom in emigration and visitor applications means the consulate, usually deserted on most weekday afternoons, is jammed with Armenians and other Soviets.

''It's like the Metro out there,'' said U.S. Consul-General Max Robinson, gesturing to the consulate's main room but referring to the busy Moscow subway.

Piles of visa application forms in Russian and extra chairs have appeared to cope with the flow of Soviets.

Each day the applicants arrive by the dozens, sometimes hundreds, to present their Soviet documents authorizing the visit to the two burly Soviet policemen who stand guard outside the embassy entrance. Once inside, they face another security check by the U.S. staff, straining the young Marine guards' command of Russian.

At the consular section of the aging compound, the prospective emigres and visitors dutifully copy sample application forms displayed around the waiting area, which is adorned with a map of the United States and a poster from Texas.

This week, a team of six experts from Washington is on hand to computerize the consulate files ''because we're so busy,'' Robinson said.

The consular staff generally start work at 8:30 a.m. and are often around until 7:30 p.m. to process visa applications, he said.

Extra personnel, already added at the West German Consulate, are ruled out because the Soviets limit the number of U.S. staff at the embassy to 226, Robinson said.

Increased emigration mostly affects Armenians. In November 1986, Robinson said, just 50 Soviets appeared at the consulate with permission to settle in the United States.

This November, the total was 1,175. Of these, 737 applications were processed, and 673 were from Armenians.

''If the Soviets continue to give these people exit permissions, we're talking 12,000 to 15,000 people a year,'' Robinson said. ''That's significant emigration from one country to another, especially if its largely from one republic.

''It's like, 'Will the last person in Yerevan please turn out the light?''' he said, adding that as many as 80,000 Armenians reportedly want to emigrate to the United States. There is a large Armenian population in Los Angeles.

Last year, about 500 Soviets a month made individual trips to the United States, Robinson said, three-quarters of them on official business.

That number has grown to about 1,000 a month since August, when the effects of new Soviet regulations on visiting relatives abroad began to be felt.

Last month, 920 Soviets - 420 of them Jewish - got visas to visit relatives in the United States, where many of the Jewish emigres of the 1970s settled.

The increase means that Soviets of all ages are getting a rare direct glimpse at the United States and can resume contacts with family members they have not seen for years.

''It's like a miracle, I'm so happy,'' one elderly Muscovite said last week after receiving permission to go to New York to see his daughter - his only child - for the first time in 12 years.

A Western source familiar with visa issuance to Israel - handled by the Dutch Embassy since the Soviets severed ties with the Israelis in 1967 - said about 8,000 visas have been issued this year compared with 950 in all of 1986.

The source spoke on condition he not be further identified.

At the West German Embassy, ethnic German emigration rose from just 87 last January to a peak of 2,035 applications in October, said spokeswoman Christine Godknecht.

Overall emigration for ethnic Germans this year will be 18 times higher than in 1986, according to her figures.

The number of ethnic Germans visiting relatives in West Germany jumped from 2,396 in 1986 to 6,978 so far this year, Mrs. Godknecht said.