The Treasury Department is studying whether to revamp its special set of minimum prices for imported steel because of the dollar's continuing decline.

Agency officials said that the prices, which are based on the cost of producing steel in Japan may soon be too high because the yen is appreciating against the dollar much faster than the currencies of many other countries that sell steel to the United States.

The so-called trigger price program was put into effect last May to halt the flood of low-priced steel imports that U.S. producers claimed was being dumped, or sold at less than fair value, in this country. The trigger price program was designed to give the government an easy method of dealing with wholesale dumping. Dumping is a violation of U.S. trade laws.

The trigger prices are revised each quarter, in part to reflect changing production costs in Japan itself and in part to account for changes in the value of the yen against the dollar.

As the yen raises it boosts the dollar cost of Japanese products, including steel.

But other countries that sell steel to the United States, such as Canada and developing countries, have not had their currencies appreciate as much as the yen has against the dollar.

"A number of countries are beginning to claim that they can sell steel in the United States at fair value that is below trigger prices," said one high-ranking Treasury official.

If the value of the yen continues to rise against the doolar, more countries can be expected to try to prove that their fair value prices are lower than trigger prices, another government official said.

The rapidly appreciating yen is a "matter of central concern to us," said the Treasury official. Treasury personnel have been drafting options for revising the current trigger-price program, but say that they are far from coming up with any feasible alternatives.

If the yen were to stop appreciating against the dollar, the Treasury's problems might be solved, but yesterday's report of a sharp increase in the U.S. trade deficit sent the yen rising again. The yen had been depreciating recently after the Carter administration vowed to fight to keep the dollar value up.

In Tokyo yesterday, before the U.S. trade deficit was announced, the dollar climbed to 194.3 yen from 192.455 on Monday. In New York yesterday, however, the dollar plummeted to 189.3 yen.

The latest set of trigger prices, which go into effect Oct. 1, assume the dollar costs 215 yen.

Any change in trigger prices would likely evoke a sharp challenge from the U.S. Steel industry, which already claims that trigger prices are not high enough.

Yesterday the government reported a sharp jump in steel imports in July, from June's 1.36 million tons to nearly 1.8 million tons. Steel imports surged during the first four months of the year, but declined sharply in May and June, in part because of the trigger prices.

Edgar B. Speer, chairman of the giant U.S. Steel Corp., said the increase in steel imports was discouraging. He said that perhaps the trigger price mechanisms is not the temporary solution to the low-price import problem.

Lewis B. Foy, chairman of Bethlehem Steel Corp. and the American Iron and Steel Institute, said that the industry had adopted a "wait-and-see" attitude on the "effectiveness of the trigger price mechanism instituted by the United States Treasury earlier this year."

He said that a continuation of the July level of steel imports would "imply a failure of the trigger price mechanism."

Steel executives, who withdrew anti-dumping suits after the administration put the trigger price mechanism into effect, have said they will reinstitute the suits if the mechanism is a failure.

Domestic steel producers have long claimed that they are the most efficient producer of steel for the American market - if foreign makers, including Japan, are forced to sell at their full cost of production plus shipping charges.

The Treasury program was designed with that claim in mind, since to prove a full dumping charge domestic makers must not only prove that a country is selling below the cost of production, but also is damaging U.S. producers.

Foreign producers can also sell in the country below trigger prices if they can prove their "fair value price" is lower that than the trigger price. But a central feature of the trigger price program was its administrative feasibility - and the agency would probably find it difficult to handle either a raft of domestic dumping suits or wholesale claims by foreign producers that they can sell cheaper than the trigger prices.