The Soviet Union yesterday firmly rejected what it called an attempt by the Carter administration to use trade as an "instrument" of political pressure.

At the same time, the Soviets described Western interest in human rights as a form of "psychological warfare" against the Kremlin.

In a major reply to Western critics of recent trials here, Moscow accused unnamed Western powers of violating the letter and the spirit of the Helsinki accord on European security and another example of such an intensive campaign to distort the essence of a major international document."

But a Soviet statement included pointedly conciliatory remarks about a "sound trend" in bilateral relations between the Soviet Union and some members of the North Atlantic Treaty Organization.

The thrust of the statement, read by Deputy Foreign Minister Anatoly Kovalev at a news conference here, was clearly aimed at encouraging some Western European governments who have voiced reservations about President Carter's human rights policy.

Accusing Western circles of having created "a certain false duplicate" of the Helsinki accord, the statement said that "this ersatz document" is now used for mounting various campaigns designed to poison the international atmosphere and interfere in internal affairs of Eastern states.

The statement contrasted "a responsible approach" toward detente on the part of unspecified NATO governments with the "negative" attitude of the United States, which is attempting "to use trade as an instrument of bringing political pressure on the Soviet Union" and to halt official contacts "for these purposes."

The reference was to the recent cancellations of a series of high level U.S. visits to Moscow and the ban on a computer deal concluded between Sperry Rand and the Tass news agency.

In response to questions about the recent sentencing of dissidents Alexander Ginzburg, Yuriorlov, Anatoly Scharansky and other activists, Kovalev asserted that they were not tried for their dissent but purely for criminal activities.

"We reject any attempts at pressure on Soviet justice and attempts to doubt our competence," he said.

"Soviet law was established by the Soviet people and our country lives by its own laws and not according to those which are prescribed high-handedly for use from abroad."

Although the Soviet statement reaffirmed Moscow's interest in improved relations with the United States, the underlying tone of the statement was Moscow's ever increasing objection to Carter's human rights policies and his attempts to link them to the broader range of U.S. Soviet ties.

Other indicators of this position are an unusually high degree of police harrassment of U.S. diplomatic personnel in recent weeks and the sudden resumption of police questioning of F. Jay Crawford, an International Harvester representative in Moscow.

Crawford, 37, who was charged with violating Soviet currency laws, was subjected to five hours of interrogation yesterday. He was ordered to appear for another interrogation session at the Lefortovo prison tomorrow.

Crawford said the interrogater covered the same ground as when he was taken into custody in June. He said he expects Soviet authorities to keep calling him in as long as their investigation continues. His interrogators showed him no evidence, did not discuss the specifics of the charges and gave no indication when the case might be brought to trial, he added.

Crawford was arrested June 12 and spent 15 days in prison. He was freed in an unusual exchange involving the release from jail of two accused Soviet spies in the United States. Crawford and the two accused Soviets still face their original charges.

The businessman again proclaimed his innocence and said after the interrogation that he felt like "a pawn in a political chess game."

Crawford also said he was told yesterday that Soviet authorities would return personal belongings to him later this week that were confiscated from his hotel room after his arrest.