The Reagan administration, stung by recent criticism from the New Right, yesterday began an intense three-day wooing of conservatives that will include the president, Vice President Bush and nine Cabinet officers.

Attorney General William French Smith led off the unusual parade of White House suitors by responding to New Right conservatives who have accused him of stacking the Justice Department with "non-Reaganites."

Appearing before the annual Conservative Political Action Conference, Smith said, "That criticism reduces to a 'more-conservative-than-thou' assessment of which senior officials at the department supported the president earliest."

Smith, speaking in a dry, almost clinical, manner, said he had chosen senior administration appointees to his department "and I have supported Ronald Reagan in every election campaign he has waged."

"The senior officials at the Department of Justice are fully supportive of the president's policies and are doing a masterful job of effecting those policies within the constraints of the law," said Smith, a long-time Reagan friend.

Later, he added that differences of opinion were "healthy," but conservatives should "not lose sight of the basic point upon which we have no disagreement. The Reagan administration represents our best hope of positive reform during the past two generations. That opportunity must not be lost."

Though Smith didn't specify what criticism he was addressing, aides said he was referring to the current issue of Conservative Digest, published by conservative direct mail expert Richard A. Viguerie.

The cover of the monthly magazine asks: "Has Ronald Reagan's Presidency Been Captured by Wall Street-Big Business-Corporate-Executive Suite-Big New York/Houston Law Firm-Eastern Liberal-And/Or Establishment-Non-Reaganite Republicans?"

Richard S. Schweiker, secretary of health and human services, also appeared before the conference, which attracted fewer than 200 persons yesterday. Last night, Bush held a reception for the leaders of the two chief sponsors of the annual meeting, the American Conservative Union and Young Americans for Freedom.

President Reagan, Defense Secretary Caspar W. Weinberger, Housing and Urban Development Secretary Samuel R. Pierce, Transportation Secretary Drew Lewis, Energy Secretary James B. Edwards, Education Secretary Terrel Bell, U.N. Ambassador Jeane J. Kirkpatrick and presidential counselor Edwin Meese III are scheduled to appear today.

The administration's two chief economic spokesmen, Treasury Secretary Donald T. Regan and Office of Management and Budget Director David A. Stockman, canceled scheduled appearances. Interior Secretary James G. Watt and Secretary of State Alexander M. Haig Jr. are scheduled to appear Saturday.

ACU chairman Rep. Mickey Edwards (R-Okla.) maintained all the attention was only natural because "Ronald Reagan embodies most of what we're trying to achieve. I believe his policies and programs have begun to put into place the most basic tenets of the conservative movement."

But more militant New Right conservatives criticized Rep. Edwards for allowing the Reagan administration to dominate the agenda for the meeting, traditionally the year's largest conservative gathering.

"It looks like a love feast," complained John (Terry) Dolan, chairman of the National Conservative Political Action Committee. "They should welcome some criticism."

Howard Phillips, chairman of the Conservative Caucus, attacked Smith's speech at one of the few sessions where New Right conservatives were scheduled to speak. "The point is our best option is for Ronald Reagan to succeed, but it does us no good at all to close our eyes to reality," he said.

If Jimmy Carter would have proposed the same huge budget deficits as Reagan has, conservatives would be up in arms, Phillips said. "We conservatives sinned by our silence during the Nixon administration . . . We ought not to sin by silence now."