Congressional action on the State Department budget and related issues this week has greatly eased the financial "crisis" for U.S. diplomacy declared several months ago by Secretary of State George P. Shultz, department officials said yesterday.

President Reagan's statements in signing the State Department authorization bill Tuesday also have eased other controversial restrictions on U.S. diplomacy.

These include a requirement for polygraph tests for members of the department's Diplomatic Security Service and congressional demands that the Palestine Liberation Organization office in New York be closed, according to the officials.

Shultz told assembled department employes Sept. 18 that major cutbacks in Foreign Service and Civil Service personnel were being contemplated and that two embassies and 13 consulates might be closed as a result of an $84 million cut in the department's personnel budget, which he said was being "brutalized" by Congress.

Subsequently, aides to Shultz drew up plans to eliminate 1,270 jobs, about 8 percent of the department's work force, causing what was described as the biggest blow to morale since the "witch-hunt" days of the early 1950s.

About $60 million of the $84 million shortfall was taken care of in the legislation passed recently by Congress and signed into law Tuesday by Reagan, according to preliminary departmental analysis.

"Nobody is talking about Rifs {reductions in force} or furloughs at this point," said an official familiar with the details. "We can probably take care of necessary reductions through attrition."

The official added that a "fairly Draconian hiring freeze" is likely to remain in place. Some posts abroad may have to be closed in coming months to keep department spending within the narrow limits required by the new budget and the anticipated austerity in the fiscal 1989 budget, the official said.

The post closings will be facilitated by a two-year waiver of restrictions on such actions. This waiver was contained in the catchall continuing resolution measures passed by Congress and signed by Reagan Tuesday.

"We have a stay of execution, not a pardon" in the budgetary crisis, a State Department official said.

The American Foreign Service Association, the department's labor union, called the upshot of the congressional action a "temporary reprieve on cutbacks" and said its lobbying and publicity efforts deserve some of the credit.

Shultz, who threatened to resign two years ago over imposition of polygraph tests on department personnel generally, fought to the end against congressionally imposed tests for all members of State's Diplomatic Security Service.

Congress did not yield, but Reagan, in signing the State Department authorization bill, declared, "I am interpreting this requirement consistent with my position concerning the discretion of agency heads to determine when polygraph examinations will be conducted in specific cases."

That appears to leave the matter up to Shultz, who has accepted the so-called "lie detector" tests as an investigative tool with the consent of the individual concerned but rejects such tests as a routine condition of employment for department personnel.

Reagan also made statements qualifying his acceptance of the congressional provision insisting on closing the PLO's U.N. Observer Mission in New York. The State Department issued a statement yesterday amplifying Reagan's remarks by saying that this provision "may infringe on the president's constitutional authority" and that consultations will be held with Congress.