In the wake of reports of widespread executions in China, Peking has published a lengthy expose of police spying and torture and warned law-enforcement officials against overuse of capital punishment.

The 4,500-word report by China's Public Security Ministry, broadcast by Peking Radio and monitored here, describes cases during the past 10 years of forced confessions and torture of disagraced Communist Party members. It forbids any recurrence of such practices.

"Discretion should be exercised in arresting people and especially in executing people," according to the broadway of the article appearing in Monday's official People's Daily.

The length of the report and the amount of detail provided, as well as the prominence of its display in China's leading national newspaper, confirmed the suspicion of China specialists here that the abuse of people power in China has been much more widespread than previously acknowledged by Peking.

Also, the frankness with which torture is discussed surprised some China-watchers here.

No figures were given of the actual numbers of China executed and tortured during the past decade, although the repeated refinencies to the practices indicated that they will still continuing.

The fact that Peking would make public such a damaging report, knowing that it would inevitably reach the outside world, seems to demonstrate the importance assigned by Peking to getting the message across to its own people.

In what might reflect unusual Chinese sensitivity to Western reports of widespread executions in the lasts few months, the official New China News Agency's brief English-language summary of the report was devoted largely to the sections on capital punishment.

"In cases where it is marginal to execute, under no circumstances should there be an execution and to act otherwise would be a mistake," the report quotes the late Communist Party Chairman Mao Tse-tung as saying.

In cases of capital crimes that have not drawn much public ire, convicts should be granted a two-year reprieve, it said.

Mao was again quoted as saying, "Following this policy of prudence, we can avoid mistakes and win popular sympathy."

Scattered wallposter announcements of executions read by foreign travelers in China indicate that most of those sentenced to firing squads recently have been convicted of non-political crimes such as murder, rape and robbery.Analysts, bolstered by reports from credible travelers, remain convinced that there have been several executions in the last few months for political opposition to the new administration of Chairman Hua Kuo-feng, although the Chinese usually use only the vaguest terms in reporting such cases.

Some wallposters speak of executions of "counterrevolutionaries" which in China could describe anyone from a burglar to an anti-Hua leafleteer. A broadcast this month from troubled Fukien Province told of three apparent anti-Hua activists convicted at a public rally for theft of party documents, slander and inciting to riot. The broadcast said, "armed public security fighters immediately led these three . . . out of the rally site to exercise the dictatorship of the proletariat," a term known to have been used at times in the past as a euphemism for execution.

The report by the Public Security Ministry, which runs China's national police force, in effect calls for a return to the administrative safeguards of the late 1950s and early 1960s. Before 1966, the year Mao launced his youth-led assault on entrenched bureaucrats, law enforcement officials apparently followed stricter procedures for clearing punishments through the Communist Party chain of command. They were supposedly guidde by Mao's 1956 statement: "In clearing out counterrevolutionaries in party and government organs, schools and army units, we must adhere to the policy started in Yenan (the Communist base in the late 1930s and early 1940s) of killing none and arresting only a few.

Now the Hua administration has entered the second year of its effort to erase the influence of four leading Politburo members - including Mao's widow Chiang Ching - whom Hua and several military leaders purged last year. Although there were some policy issues involved in last year's power struggle - like Chiang Ching's preference for enthusiastic young party officials over experienced veterans - it largely seemed to crown from long-standing personal vendettas that had different roots in different provinces.

Now some provinces are chided for being too easy with Chiang Chiang's allies and some, according to the Public Security report, are warned about being too harsh.

Authorities in kiangsi Province, for instance, did not seem to have mercy in mind when they warned in a broadcast Saturday that followers of Chiang are "still living and are not reconciled to their defeat. We must never be kindhearted and lenient toward the enemies."

The Public Security Ministry report devoted most of its space to accounts of abuse of police powers by Chiang and others.

Officials who displeased them "were even put in jail and tortured to death," the report said. They used torture and forced confessions in Mao's campaign against the bureaucracy even though Mao said in December, 1972: "Who formulated this kind of fascist-type interrogation method? It should be totally abolished."

The report also said party regulations "strictly forbid public security organs to spy within the party" even though it said the police had compiled or manufactured, information to be used against some officials.

The report indicated several maligned police veterans had been restored to their jobs in Public Security bureaus. Peking sources reported that Chao Tsang-pi, a veteran party leader also reported to have suffered during Mao's late 1960s attack on the bureaucracy, has been appointed public security minister. If so, he would be succeeding Hua who kept the post after being elevated to the party chairmanships. There has been no official report on this, but a low profile may be advisable in light of unconfirmed reports that two of his predecessors were assassinated.