Hustler Magazine owner Larry Flynt was shot and critically wounded yesterday outside the courthouse here where he was being tried on obscenity charges.

Flynt and one of his attorneys, Gene Reeves of Lawrenceville, were walking back from lunch when an unidentified man fired two shots at them, police said. Flynt, 35, was hit in the stomach and was listed in critical condition following a three-hour surgery at a local hospital. Reeves was hit in the arm and abdomen and was listed in satisfactory condition.

Although a number of people heard the shots, no one saw the shooting, police said. There were conflicting reports. One held that the shots came from a passing car. Another said that as Flynt and Reeves came to a corner, a pulled up, a man got out, fired two shots, got back in the car and fled.

"I was about 20 feet behind him. I heard a loud retort and looked to see if a car had backfired," said Neil Shister, a reporter for the Atlanta Gazette, recently purchased by Flynt. "I immediately smelled gunpowder. Larry had fallen down and was clutching his side."

Although Flynt's obscenity trial was a controversial one in conservative Gwinnett County, northeast of Atlanta, he had no bodyguards. He was not armed.

"For a man as controversial as he is, he's totally accessible," Shister said.

No threats had been made on Flynt's life, said another of his attorneys, Herald Price Fehringer of Buffalo. "We knew when we came into this county that it was conservative and there would be some hostility towards us," Fehringer said. "But I never thought there would be anything vicious as this."

State court Judge G. Hughel Harrison declared a mistrial shortly after the shooting.

A similar case scheduled for May in Fulton County (Atlanta) has been suspended.

Flynt's wife, Althea, was flown here from Columbus, Ohio, in a private plane.

Also arriving was Ruth Carter Stapleton, President Carter's sister and a faith-healing evangelist who is credited with converting Flynt to Christianity last year.

The shooting occurred during a one-hour recess in Flynt's testimony on the final day of the week-old trial.

Flynt, who is appealing a conviction for pandering obscenity in Cleveland, was being tried here on charges of distributing obscene materials - the August 1977 issue of Hustler.

Flynt founded the magazine in July 1974 as an outgrowth of a newsletter for his Hustler club in Columbus. Last year he stepped down as publisher and announced that the publication would take a new approach to sexuality to reflect his new religious views.