The Soviet Union is plainly ready and even eager to clash head-on with the Carter administration over human rights as the Belgrade conference opening Wednesday to review how well the 1975 Helsinki accords on security and cooperation in Europe have been carried out.

Instead of the atmosphere of detente that the Helsinki document was supposed to encourage, the follow-up meeting comes in a period of greater East-West acrimony, at least as far as Soviet-American relations are concerned, that at any time in the 1970s.

The Helsinki accords were signed by the United States and the Soviet Union at a 35-nation summit meeting Aug. 1, 1975. At the meeting, which had long been sought by the Soviet Union, the West acknowledged existing borders in Eastern and Central Europe. In return, the Communist states pledged to liberalize policies in a variety of areas, including human rights and freedom of the press.

The Kremlin denounced Carter this week, linking him for the first time to signed a report accusing the Soviet bloc of not fulfilling pledges to make concrete improvements in humanitarian areas. In presenting the report, Secretary of State Cyrus Vance said that the U.S. objective at Belgrade would be to avoid "poliemics."

"Let me say from the start," Vance declared, "that no nation's record is perfect and we will accept constructive criticism of our own record just as we ask others to do."

But Moscow is clearly not in the mood to be congenial. Summoning terms normally reserved for those the Soviets dislike most, the official news agency Tass said Carter had used "the most absurd and wild concoctions borrowed from the stock-in-trade of reactionary bourgeois propaganda" in defense of dissidents.

Until recently the Soviets had played down the significance of the Belgrade gathering as a review of how the complex document - which also covered political, military and economic issues - was being implemented. As merely a follow-up to the Helsinki summit of 33 European countries, the United States and Canada, the meeting was perceived here as a relatively brief and low-level affair.

The Soviets seemed to be planning to concentrate on future steps, such as a Warsaw Pact proposal for renunciation of first use of nuclear weapons in Europe and conferences on transportation and the environment.

But since the United States, in particular, appears determined to cofront the Soviet bloc with a "specific"tally of shortcomings in human rights along with restrictions on the free exchange of people and information between East and West, Moscow is certain to retort sharply.

The debate could well begin even in the early days of the conference, when sensitive questions of the agenda and procedure are to be discussed. Substantive matters, however, are to come up at the second stage of the meeting to be convened in the fall.

"The socialist states," said Tass, "have no reason to avoid a discussion on human rights. On the contrary, it is the socialist countries that strictly observe the relevant stipulations of the [Helsinki document] and they believe - and life itself daily conforms it - that socialism and socialism alone, consistently insures genuine democracy and the broadest political, civil, economic and social rights of man."

Based on what has appeared in the Soviet press and what sources are saying privately, the Kremlin argument at Belgrade's will be built around these three contentions:

The West's record in human rights is far worse than the East's. The Soviets and their allies have been rounding up every available example of such items as discrimination against minorities and surveillance of political dissenters by the FBI and CIA, dating back to the 1950s. They will hammer at fundamental points like unemployment and poverty, which the Kremlin contends are also violations of human rights.

The West has failed to fulfill concrete provisions of the accord. The Soviet bloc has amassed statistics on how many books have been translated, movies shown and tourists permitted that are intended to portray the Western countries on the whole as laggards. Certain to be prominent was the recent refusal of the State Department to give visas to a delegation of Soviet trade unionists, a practice that the Carter administration had promised would be ended.

The dissenters in Eastern Europe are merely agents by Western intelligence agencies, incited by diplomats and journalists to subversive activities. This may well be the most contentious matter, since the Soviets especially have mounted a major press campaign along those lines and hold one prominent dissenter, Anatoly Scharansky, on an allegation of spying for the United States.

The Soviets will doubtless claim also that President Carter's human-rights stance represents a violation of Helsinki provisions on non-interference in the internal affairs of other signatories. But the problem with that approach is that it would hamper the Soviets in their commenting on internal American issues.

With the United States and Soviets so obviously on a collison course at Belgrade, prospects that the conference might produce some meaningful improvement in East-West relations seem small. The Kremlin will not back down on its insistence that it has fulfilled the letter and spirit of the accord. It is hard to imagine, that Carter, having stated his views so flatly, would moderate them much now.

The danger, therefore, is that Belgrade will become a forum for recriminations that will render the Helsinki document useless. The best that can be hoped for, Western diplomats here say, is that something beneficial might emerge from everyone's having his say. But what that might be - given the current angry mood in Moscow - no one can say.