A 10-day U.N. conference on the Palestine issue gets under way here Monday amid the most extensive security arrangements ever mounted in Switzerland.

The conference, requested last year by the U.N. General Assembly as a "comprehensive international effort to find ways to enable the Palestinian people to attain and exercise their legitimate rights," is being boycotted by the United States, Canada and Israel on grounds that it will be little more than a forum for anti-Israel rhetoric.

About 1,000 delegates from 100 of the United Nations' 157 member countries are expected to be here for the conference, but U.N. officials say that about half of them will be people already in Geneva assigned to diplomatic missions here.

A number of western nations have said they will be represented only by nonvoting observers. Of the 10 states of the European Community, for example, only Greece, which follows a generally pro-Arab foreign policy, is expected to send a voting delegation to the conference.

Also attending the session, which is to end on Sept. 7, will be a number of nongovernmental organizations accredited to the United Nations, including the Palestine Liberation Organization. Today the PLO's office in Tunis said its observer delegation to the conference will be headed by Farouk Kaddoumi, head of the PLO's foreign department. But yesterday, U.N. and Swiss officials said that, despite PLO denials, they still expect PLO Chairman Yasser Arafat to make a brief appearance at the conference.

According to a draft conference agenda circulated here this week, the delegates are expected to discuss the Palestinians' "right to self-determination," their "right to a sovereign state in Palestine" and their "right to full compensation for damage to their national and human resources."

Delegates also will be asked to vote on a final resolution, already drafted in outline, that calls for creation of a Palestinian state with its capital at Jerusalem, a new Middle East peace conference with full PLO participation and U.N. Security Council consideration of an embargo against Israel if it fails to give up Arab territory, including East Jerusalem, seized since the 1967 war.

The draft agenda makes no mention of U.N. Security Council resolution 242 of 1967, considered by many countries, including the United States, as the proper basis for any future Middle East peace settlement.

Because of worries over the presence of the strife-riven PLO and possible demonstrations by Jewish protest groups, the conference, which is being held at the Palais des Nations, headquarters of the European office of the United Nations, is being guarded by 2,000 Swiss soldiers and an estimated 1,000 uniformed and plainclothed police.

The Swiss troops, drawn largely from tank units based in the German-speaking part of the country, began moving into position Thursday, bringing tanks, antiaircraft guns and automatic weapons with them. Over the previous week, Army engineers had surrounded the 2.9-mile perimeter of the Palais with wooden fences topped by barbed wire. They have also sealed off nearby streets, including the Avenue of Peace, on which the U.S. and Soviet missions are located.

Troops also are stationed at customs posts on the Swiss-French border and at Geneva's Cointrin International Airport. Traffic in the Geneva area has become chaotic with the closing of 15 small border posts, long security checks at the frontier and spot searches of automobiles on city streets for weapons and explosives.

Inside the Palais des Nations, where about 2,500 U.N. employes work, U.N. and Swiss police are using metal detectors at checkpoints in corridors leading to the two meeting rooms set aside for the conference. Only two security agents on each delegation will be allowed to carry handguns and then only if they have gotten advance written authorization from Geneva police. The agents must deposit their weapons in a "gun check-in room" before entering the conference area.

The decision to go all-out with security measures here is a reflection of official Swiss displeasure at being obliged to host the conference. New York, Paris and Vienna had turned down requests to host it on security grounds. Switzerland, which does not belong to the United Nations, also tried to get the conference moved elsewhere, but desperate U.N. officials invoked a postwar agreement whereby the Palais des Nations is the extraterritorial property of the United Nations.

This move and the high cost of the security arrangements--estimated at $5.7 million--brought angry statements this week from the usually low-key Swiss government.

In a newspaper interview, Edouard Brunner, state secretary-designate of the Foreign Ministry, called the conference a "useless show," and the Federal Council, Switzerland's executive branch, said in an official statement that it was only sending observers to the conference. It warned that being forced to hold the conference in Geneva "will hardly help to convince the Swiss people that Switzerland should join the United Nations." Switzerland, which already belongs to many U.N. agencies, will hold a referendum on full U.N. membership in 1986.