A government advisory panel warned yesterday that President Reagan's economic policies will result in fewer jobs, greater welfare dependency and a higher crime rate "that could lead to social chaos."

The exceptionally sharp criticism was made in the final report of the 15-member National Advisory Council on Economic Opportunity, a congressionally created body whose members are presidential appointees. The 14-year-old council is marked for administrative death Oct. 1.

Adding to the sting of the council's parting shot was a separate statement by its chairman, Arthur I. Blaustein, who accused the administration of "separating economic theory from social policy and pursuing the former at the expense of the latter . . . ."

"There is a price to be paid for the reduction of human and social services," Blaustein said. "That price is that these cutbacks will not reduce crime; they will increase it. They will not promote better family life; they will destabilize it. They will not increase respect for the law; they will weaken it."

The council chairman said that Oct. 1, when the administration's $35 billion cuts in social and other federal spending take effect, "will be remembered as a day of infamy, for it will mark the worst massacre of social and human service programs in American history."

But White House officials, already stung by the labor-sponsored demonstration that brought more than 250,000 people to Washington Saturday to protest Reagan's policies, strongly denied the council's charges.

"We're aware of the general thrust" of the report, said Mark Weinberg, assistant press secretary to the president. "But the president's strong belief is that his economic program, which will not produce instant miracles, will, over a steady course, produce prosperity for all."

Weinberg said Reagan "understands the concerns and frustrations" of those who say his economic policies are hurting working people and the jobless poor. But it is the president's belief that "the true enemy of working men and women is the sick national economy," the spokesman said.

"He does not believe that the kind of course that he is pursuing will bring the type of adverse conditions that some are predicting. There is no one more more interested in improving the economy" than the president, Weinberg said.

"That's no answer," Blaustein, a Democrat, responded. "The president's economic program will not provide jobs for the country's 29 million poor people. It'll mostly provide benefits for business."

Blaustein said his comments and the committee's report were not influenced by partisan considerations or the council's imminent demise. "These conclusions were reached long before there was an announcement of phase-out for the council," he said.

Among the conclusions of the report are:

* Poor women, particularly those rearing children alone, will be hardest hit by any reduction in social services. Two out of three poor adults are women, according to the report, which said the United States is "experiencing a 'feminization of poverty.' "

* Different reasons exist for the kinds of poverty affecting women and men--and the difference frequently makes women more vulnerable. "For example, after a divorce, mothers must often bear the economic as well as emotional responsibility of child-rearing, a burden that often impoverishes the family."

* Social welfare policy should be refocused to provide services such as "quality day care" that can help wage-earning mothers keep their jobs and care for children.

* The government, which under Reagan is moving to reduce federal intervention in private-sector hiring practices, should do more to eliminate "structures and practices that bar women from jobs now held by men with similar education, skills and experience in the labor force."

* Nearly 11 million people have been removed from the nation's poverty rolls in the last decade, largely because of federally funded social service programs.

* The council's research into the history and performance of the social service programs indicates that their benefits outweigh their costs, that "these federal programs do work; that they do help people get out of poverty; and that the delivery systems are providing the necessary basic human and social services."

"The council is well aware that the economic difficulties facing our nation are complex and often seem overwhelming," the panel said in its joint statement. "But these difficulties cannot be used as an excuse for reneging on our social and moral commitments as a nation."

The council also expressed misgivings about Reagan's drive to give states more responsibility for the administration and funding of welfare and social service programs.

"We are deeply troubled by the notion that national issues, ones that require national policy and programs and that are a part of our national purpose, should suddenly devolve to the states. The issue is not federal versus state responsibility; rather, it is the diminution or avoidance of any national standards of responsibility and accountability," the council said.