Soviet Defense Minister Dmitri Ustinov launched a wide-ranging attack on the United States and its Western allies today, accusing them of plotting to renew the cold war and preparing for hostilities with the Soviet Union.

In the most authoritative response thus far to President Reagan's tough anti-Soviet rhetoric, Ustinov dismissed charges of complicity with terrorists as an "evil-minded" American ploy, rejected any renegotiation of the Soviet-American strategic arms limitation treaty and accused Washington of preparing to achieve its global goals through a "preemptive nuclear" strike against the Warsaw Pact nations.

Soviet armed forces must "tirelessly perfect combat readiness" to meet the Western challenge, Ustinov said.

The tough statement by the marshal, who is also member of the 14-member ruling Politburo, is seen here as setting the tone for the Soviet Communist Party's 26th congress, which convenes Monday to set foreign policy and economic goals for the country for the next five years.

"The imperialists are working out various aggressive military and political doctrines directed against the countries of the socialist community, and are continuing intensive preparation for a new world war," he said in an article in the Communist Party daily Pravda commemorating Soviet Army Day, which coincides with the opening of the congress.

Soviet President Leonid Brezhnev is expected to make similar tough statements in his keynote address to the congress Monday, Soviet sources here indicated.

Ustinov offered no new suggestions or ideas on how the United States and the Soviet Union can improve their relations. The address is an annual ritual but takes on added significance because of the bitter atmosphere now gripping Moscow-Washington relations since the Reagan administration took office a month ago. Soviet propaganda has assailed Reagan and Secretary of State Alexander Haig for charging that Moscow supports international terrorism.

The 72-year-old defense chief said the charges were an "evil-minded deception" to cover up Western complicity in subversion aimed at the socialist nations. "Terrorism is the weapon of extremism and neofascism, one of the darkest symptoms of the moral and political crisis of capitalist society, the incarnation of lawlessness," Ustinov said. But any national liberation movement supported by Moscow, he said, "has a progressive character, and its legality has long been recognized by the international community and confirmed by resolutions of the United Nations."

Ustinov accused communist archrival China of joining the United States in mounting "provocations" against Moscow's Indochinese allies -- Vietnam, Laos and Cambodia. He also sid imperialism is taking "subversive actions" to "destabilize the atmosphere" in Poland with efforts to "discredit socialist power and weaken socialist solidarity."

It is expected that the Polish crisis will not be widely discussed at the congress, which is a ritualistic gatherin of about 5,000 Soviet delegates to endorse the Politburo's policies and hail Brezhnev, 74, for another five-year term as supreme Soviet leader.

It seems likely, however, that Warsaw Pact leaders will meet behind the scenes for their first discussion of Poland since last December's emergency gathering in Moscow shortly after Stanislaw Kania came to power in Warsaw. Kania's speech to the congress will be intently scrutinized by foreign observers for signs as to how he intends to respond to likely Kremlin pressures to roll back the concessions to independent trade unions and private farmers made by the party through the months of crisis in Poland.

Ustinov in today's article denied that the Kremlin has raised its nuclear missile forces, charging that the United States is developing new land- and sea-based nuclear weapons. "The Pentagon is counting on nuclear weapons to achieve the global strategic goals of the U.S. by carrying out preemptive nuclear strikes against the Warsaw Pact countries," he declared.

He said the Soviet Union does not seek strategic superiority and called the SALT II treaty, which Reagan says must be renegotiated, an effective barrier against the arms race. Renegotiation, he said, "quite obviously radically contradicts the interests both of Americans and Soviet peoples, as well as the interests of all mankind."

The speech is a measure of how far relations between the two superpowers have deteriorated since the last party congress in 1976. Then, Brezhnev pledged to pursue detente with "redoubled energy." The Kremlin had scored impressive diplomatic gains, chiefly in the 1975 European security agreement that recognized Soviet postwar hegemony over Eastern Europe and accepted the status of East Germany. SALT II -- now lapsed but still observed by both countries -- was the centerpiece of Brezhnev's policy of negotiating major dangers with the United States.

But since then, the continued Soviet military buildup, and foreign military actions such as the invasion of Afghanistan in December 1979 have rewritten the scenario for world relations. Moscow has been condemned for agression by a majority of the United Nations and most Islamic countries, where it assiduously cultivated good relations. The possibility of Soviet intervention in Poland has set Western Europe on edge and brought hardened attitudes toward Moscow across the continent.

Meanwhile, the burdens of the Soviet arms buildup have meant deepening troubles for the civilian economy. There are widespread shortages of common consumer items -- such as needles, buttons and eyeglasses -- and agricultural problems have worsened in recent years despite outlays of billions of rubles for new equipment and fertilizers for the wasteful collective-farm system.

It is unlikely that the congress will take any major steps to rectify these problems, although Brezhnev has promised that consumer goods will get the lion's share of investment through 1985. A similar promise in 1971 faded when the Soviets stepped up spending on basic industries to feed the defense establishment's expansion.

It will be Brezhnev's fourth party congress as leader, and although his personal political power stands at the highest point in his long career because of the retirement and death of former premier Alexei Kosygin last year, many of the same problems that confronted him in 1964 when he first came to power remain unsolved.