Democratic members of the House subcommittee on post-secondary education grilled three top administrators of federal cultural agencies yesterday and charged them with toeing the Reagan party line on the budget cuts in their agencies.

"Was it necessary, when you took the job, to agree to accept these cuts and go out and defend them?" asked Rep. Peter Peyser (D-N.Y.) of Frank Hodsoll, chairman of the National Endowment for the Arts, at a budget authorization hearing.

"When I left the White House," said Hodsoll, "I was told that everything in the arts would be done fairly, and I would have total input."

Peyser countered, "What is fair about a 30 percent cut of the program? We've listened to Cabinet members all week who've fought for years for programs, and now say they can get along fine with these programs. I'm telling you that from every group I've talked to in the arts , this will be a catastrophe."

Reagan has proposed cutting NEA funding from $143 million to $100 million and NEH funding from $130 million to $96 million. Both Hodsoll and William Bennett, chairman of the National Endowment for the Humanities, support the cuts.

Similarly, Lilla Tower, the Reagan-appointed director of the Institute for Museum Services, said that she supports the Reagan budget that abolishes the agency she now heads. "The administration believes that the best climate for museums in the years ahead is a responsive economy from which they can continue to draw upon private and local initiatives," Tower told the subcommittee.

"We've been hearing this all week," subcommittee chairman Paul Simon (D-Ill.), said to Tower. "You just drop the word, 'museum.'--'The administration believes that the best climate for blank in the years ahead is a responsive economy from which they can continue to draw upon private and local initiatives.' " The remark was greeted with chuckles throughout the hearing room.

"I've always held the role of director as being an advocate of the program," Peyser said to Tower. "You're coming through as an apologist."

"I'm not an apologist for the administration," Tower responded. "I strongly support the president and what he's trying to do. I view myself more as a realist than an apologist."