Former presidential aide Michael K. Deaver, who said in his new book that his downfall was hastened by many White House enemies, said yesterday that, given the chance, he wouldn't change anything he did during his five years as President Reagan's deputy chief of staff.

"I did always what I thought was right for the president," said Deaver, who was convicted last month of lying to Congress and a federal grand jury about the lobbying business he formed after leaving the government in May 1985.

In an interview about his new book, "Behind the Scenes," the former Reagan confidant said that although his troubles were caused in part by those who viewed him as "the guy who wielded the ax," he had no desire to revise what he did as one of the president's top aides.

The one thing he said he wished he could change was "my own image after I left the White House." Deaver's role as a high-profile Washington lobbyist was one of the factors that led to congressional and criminal investigations into his lobbying.

Deaver said it would be hard for anyone who had been so close to the center of power in Washington to remain in the city without developing some of the "overconfidence" that contributed to his downfall. "It would be a lot different if you left town," he said.

In the book, expected to begin appearing in Washington bookstores this month, Deaver describes numerous incidents in which he and Nancy Reagan sought to soften the president's stance on conservative issues or force the resignations of aides who had become controversial.

Those disputes, on which Deaver and the first lady seemed kindred spirits, were not so much struggles over philosophy as they were over the specifics of the issue facing the president, Deaver said yesterday.

For example, the book tells of Deaver's effort, after he left the White House, to dissuade Reagan from making a televised appeal on behalf of the Nicaraguan contras.

"I worked 4 1/2 years to keep the right-wingers from getting you out in front on this Central America issue," Deaver said he told the president. "Now, Mr. President, for you to go on television to push for more public support of the contras is a mistake. It is the wrong cause at the wrong time."

Nancy Reagan also shared concerns about the president's Central American policies, but the book said they were unable to sway the president, who cut short Deaver's arguments, saying, "No, no, I have to do it. I believe in it."

The president that Deaver portrays in the book "holds to a harder line, is less quick to adjust and less willing to compromise than Nancy." Nonetheless, Deaver, who has been as close to Nancy Reagan as to the president, said that she continues to exercise considerable influence over the president.

Deaver said yesterday that he hoped his book would help people to see Reagan as a less rigidly conservative president. "He is by his nature a very reasonable man," said Deaver.

The 263-page book, in which Deaver remains an unabashedly strong admirer of the president, reportedly has infuriated Nancy Reagan with some of its glimpses of the Reagans' private moments.

Some White House aides have suggested that her reaction may have ruined Deaver's chances for securing a pardon from his perjury conviction. The president and Nancy Reagan severed their more than 20-year relationship with Deaver after his Dec. 16 conviction, Deaver said yesterday.

He said that he had sent a copy of the book to the White House, but was uncertain if either the president or Mrs. Reagan had read it.

Most of the snippets of the Reagans' life at the White House are flattering, and Deaver said yesterday that he hopes the Reagans will view the book that way when they read it. Deaver said he is planning a national tour to promote the book, starting next month.

He acknowledged removing from the book a line about drinking a quart of scotch and eating three rolls of breath mints a day as a secretive alcoholic. Deaver said he cut the line, which his co-author Mickey Herskowitz had added, because "I just didn't think it was pertinent, how much I drunk."

Deaver, who had been expected to make alcoholism a central aspect of his defense, declined to discuss details of his case, noting that it is certain to be appealed. He faces a possible prison sentence of up to 15 years at his sentencing Feb. 25.

In his book he offers a defense against the charges of lying, supplying explanations for his actions that were not made during his trial because of his controversial decision not to mount a defense.

In the book, he denies lying to investigators about the contacts he made with Reagan administration officials as a lobbyist, and says he simply didn't remember the meetings.

"You can be made to look foolish or sometimes evasive by repeating that you do not remember. But sometimes there is no mystery. You just don't remember," Deaver said.