Polish leader Wojciech Jaruzelski gave up his post as premier today and began shuffling top officials in a move to consolidate his authority and prepare a fresh drive to stabilize the country.

Jaruzelski formally resigned his post in the opening session of the newly elected Polish parliament, or Sejm, and instead took the position of president of the Council of State, which makes him the ceremonial state executive of Poland.

The 62-year-old general, who retains his key positions as first secretary of the Communist Party and commander-in-chief of the armed forces, nominated a loyal follower, Deputy Premier Zbigniew Messner, to replace him as chief of the government.

Messner, 56, is an economics professor who has risen to prominence in the government and the Communist Party since Jaruzelski became premier in February 1981. As the first deputy premier, he was responsible for overall coordination of economic policy.

The widely anticipated government reorganization, which was approved by the 460-member Sejm in lopsided votes, had the effect of normalizing the formal structure of authority in Poland for the first time since 1981 by recreating the separation between Communist Party and government leaders standard in Soviet Bloc countries.

Jaruzelski's shift and accompanying changes in top official posts also appeared to consolidate the general's leadership and position him to control crucial preparations for the Communist Party congress scheduled for next year, political activists here said.

The tone of the government's new course was set by Jaruzelski in a speech to the Central Committee last night that described his administration as having "crossed another threshold" toward national stabilization following parliamentary elections Oct. 13.

The message outlined a more aggressive government approach in carrying out a reform of the economy, hinted at an expected release of some political prisoners and suggested increased official tolerance for debate and criticism in the media.

Other party spokesmen made clear that Jaruzelski will continue a hard line against opponents in the banned trade union Solidarity and the Roman Catholic Church. At the same time, government officials appear to be hoping for improved relations with the Reagan administration and other western governments and for an increase in western economic assistance.

The government changes were in part meant to assure foreign observers both in the West and in the Soviet Union that Jaruzelski is gradually leading Poland away from the turmoil of the Solidarity era, party activists here said.

Today, veteran government observers perceived a deliberate effort to create an atmosphere of normalcy around the new Sejm and government. Jaruzelski appeared at the session in the parliament chamber wearing a gray suit rather than his customary military uniform, and a glowing recital of his accomplishments as premier omitted any reference to Solidarity, the period of martial law that accompanied its suppression or the role of the military in ruling the country during that time.

Jaruzelski's control over government policies is expected to be strengthened by personnel shifts in the Sejm, Council of State and Council of Ministers. Changes in the Cabinet and party leadership will not be announced until early next week.