University scientists and administrators, backed by the National Academy of Sciences, are resisting efforts of the federal government to further restrict Soviet scientists' access to technological information during visits to American campuses.

The Reagan administration has become increasingly concerned that much of the Soviet Union's military strength is based on its acquisition of U.S. scientific and technological knowledge and developments.

The confrontation was joined Dec. 14 when Stanford University received a routine letter from the National Academy about a Soviet robotics specialist, Nikolay V. Umnov, who wanted to visit four U.S. universities, including Stanford. The letter said that, on State Department orders, Umnov would have to be put under certain restrictions if he were to visit.

Stanford refused to go along with the restrictions, and Stanford President Donald Kennedy expressed his "grave concern" over federal attempts to apply restrictions to academic work.

Robert McGhee, a professor at Ohio State University who was expected to host the Soviet scientist for the longest period while he was here, has also called the State Department to back out of the arrangement. He said he had no means of policing the activities of Umnov for the six weeks he would be in Columbus, Ohio.

On Monday, the National Academy of Sciences, which runs the exchange program through which the Soviet scientist would visit, backed up Stanford's position. A spokesman said the academy will stop acting as a middle man and will no longer pass on State Department orders to universities.

The academy no longer will help enforce restrictions on the scientists' activities and access to information, at least until its officials can negotiate the matter with the State Department. Academy spokesmen said this stance has been taken because recent restrictions are "stiffer than in years past" and in some cases "difficult or impossible to enforce."

A State Department spokesman conceded that the restrictions may indeed be tougher than they have been in the recent past.

"It has a lot to do with the atmosphere in Washington, and the worry about what we are leaking away to the Soviets," he said.

The academy's sudden action this week quickened the duel between academics and the government over questions of intellectual freedom and national security. Two other recent incidents and statements have struck sparks between academics and the government.

Late last year, the State Department sent out about 600 letters questioning universities about the activities of Chinese scientists on their campuses. In a half dozen cases, the State Department estimated, universities were asked to restrict what the Chinese could see and do. Some universities, including Stanford and the University of Minnesota, refused to comply, and the matter is not yet settled.

Two weeks ago, Adm. Bobby Inman, deputy director of the CIA, told scientists that they should voluntarily submit their work for government review and possible censorship on national security grounds because much of Russia's military power is built on U.S. science.

In the latest incident, Umnov's request to visit four U.S. universities was relayed by the National Academy to Stanford, the University of Wisconsin, Ohio State University and Auburn University.

Umnov specializes in building robotic walking machines that traverse rough terrain, and he was not to be shown any details of the computer programming that runs such devices in this country.

The government specified that he was to speak with scientists only at the theoretical level. He was not to be allowed any visit to industry. He should have no access, "visual, oral, or documentary," to production research or any classified or unclassified work that might be funded by the Defense Department.

Researchers who expected to host Umnov at the four schools all questioned the restrictions, partly because the work going on at the facilities is not classified and is published regularly in international journals.

Andrew Frank, a professor at Wisconsin, said that the Russians know so much more about the field, it would be to our advantage, not theirs, to have Umnov visit.

Asked about the possible military sensitivity of robotic machines that can move over rough terrain, he said the field is still at the most basic level of research and for decades to come, "anything you can do with walkers, you can do better with motorcycles and cars."