Secretary of State George P. Shultz yesterday denounced Israel's crackdown on Arab universities in the occupied West Bank as a threat to academic freedom reminiscent of the McCarthy era in this country and said that the Israeli policy is "not helpful at all" to the Middle East peace process.

Speaking at a news conference, Shultz used uncharacteristically tough language to describe Israeli actions that have led to the expulsion of 22 foreign teachers and threaten as many as 100 others because of their refusal to sign a pledge that they will not assist the Palestine Liberation Organization.

Several of the teachers are American citizens.

"I think we should speak unequivocably about it," he said, "and people in the intellectual community, particularly those who have been through this -- you remember we had the episode of the loyalty oath -- must speak up, including people in universities in Israel. It is the same problem, the problem of freedom, freedom of thought."

Referring to the academic witch hunts associated with the late Republican senator Joseph R. McCarthy of Wisconsin during the 1950s, Shultz, a former professor and dean at the University of Chicago, told reporters: "Maybe some of you are too young to remember those days, but I remember."

His words seemed likely to provoke new tensions between the Reagan administration and the government of Israeli Prime Minister Menachem Begin, which already is smarting over renewed U.S. calls for a freeze on establishment of Jewish settlements in the West Bank.

Before Shultz spoke yesterday, a senior Israeli official in Jerusalem, briefing foreign correspondents on condition that he not be identified, contended that Israel, like the United States, has a right to impose conditions and restrictions on foreign nationals working in territory under its control.

At issue is a new regulation of the Israeli civil administration in the West Bank requiring foreign teachers at three universities -- Najah, Bethlehem and Bir Zeit -- to sign a pledge not to aid the PLO.

Edward Walsh of The Washington Post Foreign Service reported from Jerusalem yesterday that virtually all the teachers have refused to sign, and have been told they will be deported when their three-month tourist visas expire.

On Tuesday, State Department spokesman Alan Romberg issued a statement criticizing the expulsions, and Shultz took the initiative in bringing the matter up again yesterday when he was asked whether the United States might tie its aid to Israel to a freeze on settlements.

President Reagan had been expected to raise the settlements question at a meeting with Begin that had been scheduled here today. The meeting was canceled after the death of Begin's wife last Saturday caused the prime minister to break off his U.S. visit and return home.

In addressing the settlements question, Shultz said the United States has made "no link" with U.S. aid to Israel. But he reiterated the U.S. view that "expansion of the settlements is not constructive at all," adding, "just as some conditions on the West Bank are not a constructive contribution to the peace process."

"I suppose I think about it in part because I am fundamentally a university man, and the idea of asking the people who come to teach and work in a university setting -- which is, after all, a setting where we expect to have and encourage freedom of thought -- to sign oaths is just not the way to go about it," he said.

The almost emotional nature of his comments struck many who heard them as reflecting, in part, Shultz' personal feelings. But it also was a sign that the administration is increasingly concerned that the Begin government's tough West Bank policies are harming the chances for progress on Reagan's Mideast peace initiative.

At a time when the president is seeking to bring about broadened talks on the future status of the West Bank and Gaza Strip, the Arab governments have made increasingly plain that they regard Reagan's ability to moderate Israeli policy in these territories as a test of U.S. influence on Begin.

However, Walsh reported from Jerusalem, the senior Israeli official took the position that the policy toward the Arab universities "has nothing to do with the negotiations" and is "something every country does when it has problems."

The official then recited a list of U.S. immigration restrictions that he said prohibit the entry of anarchists, communists, Nazis and those who advocate the overthrow of the government.

This referred to provisions in the U.S. Immigration and Nationality Act specifying categories of persons who are normally ineligible to receive entry visas. However, U.S. law also provides a number of ways in which exceptions can be made; and, as a practical matter, many individuals who ordinarily would be barred have been permitted to teach or study at American universities.

U.S. officials also have noted that their criticism of Israeli policy, in this situation, applies not to the question of which persons are permitted to enter territory under Israeli control but to the academic freedom of teachers who are already there. The U.S. position, in short, is that Israeli authorities are using the temporary-resident status of the affected teachers as a threat to their teaching independence.