An Environmental Protection Agency official urged Congress yesterday to make substantive changes in the nation's pesticide-control law, although the Reagan administration has recommended leaving the law alone for at least two more years.

"I think the current system needs change," John A. Moore, head of the agency's pesticide and toxic substances division, told a House Agriculture subcommittee under questioning. "You can only go so far to make a silk purse out of a sow's ear."

Moore, a presidential appointee who has run the pesticide program for 15 months, urged the panel to abolish federal "bailouts" for makers of unsafe chemicals and to untangle a web of administrative procedures that can keep dangerous products on the market years after their hazards have been documented.

His testimony came as the panel opened hearings for the fifth straight year on the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).

Efforts to alter the controversial law last year failed when neither the EPA nor the White House responded to the subcommittee's repeated requests for an administration proposal.

The EPA promised in November 1983 that it would draft changes in the pesticide law, and the agency had been expected to release a proposed bill at yesterday's hearing.

Agency officials said the draft was scrapped partly because the administration did not believe that the Senate was interested in working on FIFRA and partly because "we came to an agreement that there was too much on the plate already."

Instead, Moore came to the House hearing with a carefully worded statement that called FIFRA a "fundamentally sound environmental law."

But in response to questions, he left little doubt that the EPA would like to see changes.

Asked, for example, how Congress should change the process of indemnifying pesticide manufacturers whose products are banned for safety reasons, Moore responded bluntly:

"Strike it. Strike the whole process . . . . It's broken right now and it needs fixing."

Subcommittee Chairman Berkley W. Bedell (D-Iowa) said he was "disappointed" that Moore came to the hearing without a formal proposal, but he vowed that the subcommittee would press on, with or without the administration's help.