Federal Emergency Management Agency Director Louis O. Giuffrida yesterday denied intentional wrongdoing at the agency and said recent investigations into mismanagement and fraud have been a "soul-searing trauma."

Testifying under oath before a House subcommittee, Giuffrida said he was unaware that a FEMA contracting firm called Triton Corp. had paid a $2,000 bill for him and another agency official and their wives to attend a political fund-raiser and then charged the government for the affair.

The Capitol Hill gathering featured Vice President Bush speaking at the National Republican Club.

Giuffrida and nine other top FEMA officials told the House Science and Technology investigations and oversight subcommittee that they were unable to say whether the agency had reimbursed Triton for the costs of such political events. The firm has conceded that it should not have billed the government.

Rep. Harold L. Volkmer (D-Mo.), the panel's chairman, said, "It appears to me the committee . . . is being stonewalled."

Giuffrida replied, "We don't want to stonewall anybody."

During hours of questioning, the retired brigadier general contended that he had sought to bring order to a disorganized agency, in part by adding several former military associates. He said this included establishing a fast-track payment system for contractors that might have allowed some "bad" things to happen.

The testimony was the first in public by Giuffrida and former FEMA official Fred J. Villella since several investigations of the agency began last year.

Villella strongly denounced the investigations as based on "misleading information provided to the committee" in a "climate of sensationalism seized on by the press."

He said the political nature of the charges and motives of disgruntled employes had been "ignored at my expense . . . . My reputation was permanently marred."

On other allegations raised in the hearing:

* Giuffrida and Villella denied that they intended to reside in or use for personal reasons a renovated building in FEMA's training center in western Maryland. Villella resigned last summer following allegations that he misspent $170,000 to turn the building into a residence with a gourmet stove, wet bar, microwave oven and remodeled bathroom.

In a 1983 memo, Giuffrida asked his staff, "Where are we on authorizing quarters for me on post at the training center ?"

Yesterday he testified that "the 'me' that's there in that memo is not 'me' personally" but a reference to establishing quarters for "whoever would be running the facility."

* Giuffrida denied that he had tried to influence subordinates to approve a contract to computerize an already computerized data bank. Two FEMA employes have testified that they were ordered to approve such a proposal from a firm that includes one of Guiffrida's former Army acquaintances.

A Giuffrida aide said that one employe may have made the charge because he was "galled" when Giuffrida's staff took away his reserved-parking place and that there was "no way" such an order was given.

* The panel disclosed that Giuffrida aide Ronald Face told his boss in a memo that a Triton official had pressed him about a 30-day extension of the company's multimillion dollar FEMA contract that was to have expired April 1. Face quoted the official as telling him, "If there is no action in that direction, the 4 March hearing could be disastrous."

Giuffrida denied that the contract was extended because of the memo, maintaining that the extension had been planned. "I do not respond to threats," he said. "I did not perceive that as a threat."

* Giuffrida defended taking his wife on two trips to Mexico and Europe at government expense, saying it was legal to use her as an international hostess for FEMA.