Peking's blast at Ronald Reagan yesterday represents the failure of a month-long effort by foreign policy advisers to the GOP presidential candidate to disengage him from a potentially explosive diplomatic controversy. The culprit in the failure was Reagan himself.

The dispute is over U.S. relations with Taiwan, long the insurmountable barrier to full U.S. diplomatic relations with the People's Republic of China. Reagan has been a strong backer of Taiwan ever since he visited the Island in October 1971, as a special emissary of President Nixon. Since later 1977, the public relations, firm of two of Reagan's closest aides, Michael Deaver and Peter Hannaford, has been on the Taiwan government payroll.

Reagan criticized the Carter administration's action in breaking off diplomatic and official relations with Taiwan in the late 1978 in order to establish diplomatic relations with Peking. Early in 1980 Reagan while campaiging said several times that as president he would support reestablishment of "official relations" with Taiwan.

The reaction from China was sharp disapproval in Peking's view Regan was proposing to renounce unilaterally the very basis for the arrangement with permitted full-scale ties with Washington.

Reagan's foreign policy advisers, seeking to head off a dispute which could place in doubt there candidate's diplomatic judgement as well as the future of U.S. relations with China, sought to soften his Taiwan stand. The campaign's senior foreign affairs coordinator, Richad V. Allen, after what he described as a long talk with Reagan about China-Taiwan issues, announced at the Republican National Convention a month ago that Reagan does not intend to "turn the clock back."

"Gov. Reagan recognizes the importance of our present relationship with the People's Republic of China . . . The relations that exist with the PRC and the relations with Taiwan will continue," allen said. This implied, at least, that Reagan had given up his idea of resuming "official relations" with Taiwan. On other occasion. Allen said it is not Reagan's intention to "alter or reform" U.S. relations with Taiwan.

At the Reagan camp's direction, the GOP platform adopted in Detroit made no mention of a change in the nature or form of relations with Taiwan. And after the convention, vice presidential nominee George Bush was assigned to travel to Peking to assure the Chinese that no fundamental change in relations is planned. To emphasize the point, no Bush stopover in Taiwan was scheduled.

The new trouble broke out at a press conference last Saturday near the Los Angeles airport, where Reagan appeared for a personal sendoff to Bush and adviser Allen or their trip to Asia.

Reagan, responding to questions, suggested that his previous statements mistakenly had been interpreted as advocating full dioplmatic recognition of Taiwan. "I have made it plain, I think from the very first, that I was talking about an official governmental relationship" he said.

He went on to say that the Carter administration had established a "liaison officer" in Tawian, following the shift in relations, as a "private foundation . . . not governmental." He also asserted that under the recent Taiwan relations legislation, "there are provisions for governmental relations [which] just haven't been implemented.

Reagan said he would advocate of implementation of government-to-government relations under the Taiwan legislation, and said that a "liasion office" and said that a "liaison office" in Taiwan "could be official." He then also stressed his desire for continuing improvement in relations with mainland China.

Reagan's remarks appeared to represent either lack of understanding or lack of power briefing, despite all the previous discussion and controversy on the issue.

A "liaison office" -- a governmental office short of a full embassy, such as the United States once had in peking -- is not maintained by the United States in Taiwan because Peking would not agree to such an arrangement. Any contact between Washington and Taipei must be "unofficial," the mainland Chinese insisted, and the Carter administration agreed. Under the act passed last year by Congress, the "institute" handling U.S. affairs in Taiwan is nongovernmental.

In Tokyo en route to Peking yesterday, both Bush and Allen denied that Reagan advocates a "two-China" policy, and they said again that Reagan did not intend to "turn back the clock" on China policy. However, Reagan's press conference remarks remained on the public record, and Chinese continued blasting away.