Despite 1.7 million documented cases of child abuse annually, the Reagan administration is undermining a small federal antiabuse program with funding cuts, political manipulation of grants and failure to seek the best expert advice, Rep. Ted Weiss (D-N.Y.) charged at a hearing yesterday.

Dody Livingston, commissioner of the Department of Health and Human Services' Administration for Children, Youth and Families, and Jane Burnley, associate commissioner of the HHS Children's Bureau, who oversee the program, strenuously denied the charges.

Weiss, chairman of the House Subcommittee on Intergovernmental Relations, also charged that Dorcas Hardy, the Health and Human Services Department's assistant secretary for human development services, had failed to appear to testify about the antiabuse program, instead going on a business trip to New York that Weiss implied was arranged at the last minute as an excuse. He said he intends to notify the appropriate Senate committee of her refusal to appear if, as expected, she is nominated as Social Security commissioner.

Weiss said that Michael Astrue, acting deputy assistant secretary of HHS for legislation, had told a Weiss aide Tuesday that his hearings on the programs of HHS' National Center on Child Abuse and Neglect were "too insignificant" for Hardy to attend, now or perhaps ever. Astrue denied he had made the statement, but did say he had referred to Weiss' aide's activities as a "rinky-dink" operation.

Weiss said the president's budget had asked that funds to combat child abuse and family violence (wife-beating, abuse of the aged) be united in one grant and funded at only $30.5 million in fiscal 1987, whereas for 1986, Congress granted $31 million for child abuse and $8.5 million for family violence.

Weiss also said that that "a third to a half" of grants given out for child-abuse projects were removed from the competitive system and handled "administratively," instead of strictly, according to reviewers' merit ratings. He said that in the National Institutes of Health the proportion was only 5 or 10 percent. He said he knew of no employe at the NCCAN who had any direct prior experience in the child-abuse field; and that grant reviewers, instead of being experts, were in some cases political appointees in the department or otherwise politically linked to the administration.

Burnley, bristling, said one examiner Weiss criticized was a judge with substantial juvenile experience and that others had extensive experience of various kinds.

In varying degrees, witnesses from the National Child Abuse Coalition, Child Welfare League, American Academy of Pediatrics and American Psychological Association supported many of Weiss' criticisms of NCCAN operations.