Mayor W. Wilson Goode, facing the biggest crisis of his administration, defended today his handling of the police assault on the MOVE headquarters that left at least six persons -- including two children -- dead and 53 homes destroyed by fire.

Standing firm against what he repeatedly called "second-guessing," Goode told reporters at a City Hall news conference this afternoon, "If I had to make the decision over and over again, I would do it again."

Only 17 months ago, Goode's election as the first black mayor of this often racially divided city was a source of local and national pride. Since then, his highly personal and open stewardship of the nation's fifth-largest city seemed largely successful.

Tonight, however, as city officials confirmed the deaths, Goode took his case directly to the people in a 14-minute televised speech.

The mayor announced that the city's business community had pledged $500,000 in emergency temporary assistance and that building trades unionists were at work on a plan to build 60 homes.

And he staked his political future on a promise he said he had made many times in the past: "I will tell you the truth. I will be candid. I will stand behind my word and I will make a full commitment to be decisive and move our city into a strong future."

One of the most pressing questions for Goode was the decision to drop an explosive device on the Osage Avenue row house in which several apparently well-armed members of the radical group had been holed up for days.

Goode visited the fire-ravaged West Side neighborhood this morning and told reporters he was "devastated" by what he saw: buildings that once stood shoulder to shoulder transformed into one burned-out shell after another.

He said he promised those who lost their homes that they would be "made whole" for the damage, and acknowledged that he had not expected the explosion to result in a fire.

Goode said his decision was one in which "if it works, you're a genius; if it fails, you're condemned. I'm the one who should be held accountable . . . . I made the decision and I stuck with it."

"I know the next few days will be very difficult," Goode said. "But nobody promised me a rose garden."

As the city came to grips with what had taken place, there was mostly diffuse criticism of Goode, a 46-year-old sharecropper's son whose first major political success was a victory over Frank L. Rizzo, the city's controversial former mayor and police commissioner, in the 1983 Democratic mayoral primary.

Some residents of the charred neighborhood questioned the heavy police presence and said they feared all along that children would be killed by such apparently indiscriminate use of force. Time and again they likened the confrontation to a small "war."

Some residents criticized city firefighters for not trying immediately to control the fire that resulted from the explosion. Fire officials said they hesitated because of gunfire, and Goode said the fire was "an accident."

But many others supported the mayor's decision to move decisively against MOVE after months of tolerance that eventually drew criticism from frustrated neighbors of the group.

"I am a person who believes in negotiation," Goode said. "I don't believe in confrontation. We had a well-thought-out plan. The plan was to prevent the loss of life."

Until now, the biggest crises of Goode's administration had been the need to reconstruct a damaged commuter railroad bridge quickly and to stop the city's professional football team, the Eagles, from leaving town.

Goode's only major political defeat came 13 months ago, when he supported former vice president Walter F. Mondale for the Democratic nomination for president against Jesse L. Jackson, the favorite of the city's black community. With a strong boost from blacks, who make up nearly half of Philadelphia's Democratic voters, Jackson won in the city.