A top official of the President's Commission on Organized Crime clashed yesterday with a House subcommittee when he refused its request to submit to a surprise drug test before testifying in favor of a commission proposal to require urinalysis drug testing of federal employes.

Rodney Smith, deputy executive director of the commission, angrily faced a bank of television cameras and denounced the request as a "cheap shot" and a "performance for the media."

Rep. Gary L. Ackerman (D-N.Y.), chairman of the Post Office and Civil Service human resources subcommittee, had surprised Smith when he held up a small plastic jar, said, "I think a specimen is worth 1,000 oaths" and asked him to "go into the men's room" to produce the sample "under the direct supervision" of a staff member. (Military procedures for random drug tests require a witness to ensure no substitution of specimens.)

Ackerman told Smith that he had a lab waiting to test the sample for signs of drug use.

After Smith refused to cooperate, Ackerman said, "I thank you for very eloquently proving the point that we have set out to prove."

The commission report, supervised by Smith, recommended "appropriate" drug testing for all federal, state and local employes, as well as employes of government contractors.

President Reagan has said that he supports the idea, and Attorney General Edwin Meese III has said he sees no legal problems with requiring employes to undergo drug testing as a condition of employment.

The proposal, one of many in the lengthy report, has been denounced on constitutional grounds, partly because there is no evidence of widespread drug use by federal employes.

In responding to the criticism, Smith said the commission has made "no assumption that the federal work force is somehow suspect." He added that he believes that employes found to be using drugs should be rehabilitated, not dismissed.

James Pierce, president of the National Federation of Federal Employees, called drug testing "the most insulting proposal to emerge from the Reagan administration's federal employment policies since its plan to require workers to submit to polygraph examinations. In fact, it smacks of a police state."

Opponents also have questioned the accuracy of the tests.

"Experts tell me that a person can register positive for opium after eating poppy seed rolls," Ackerman said. "Inaccurate tests have the potential to ruin a person's career."

Labs conducting drug tests for the military, which has required urinalysis since 1981, have been accused in court of mixing up service members' urine specimens, spilling urine from one sample into another and misidentifying samples with the wrong Social Security numbers.

The military services have had to overturn demotions and correct the records of personnel accused of drug use on the basis of erroneous test results