Reservations about the practicality of a national identity card that would be used to detect illegal immigrants held up presidential approval yesterday of a new immigration and refugee policy, according to White House sources.

During a 70-minute cabinet meeting devoted to immigration and refugee issues, Attorney General Willaim French Smith presented the recommendations of a presidential task force. The meeting ended without a decision by President Reagan, who took the recommendations "under advisement."

Smith told reporters afterward that there were no "sticking points" about the policy in the Cabinet.

But there are, at least, some questions about the proposal Smith endorsed for a "tamper-proof" Social Security card that would serve as a national identity card. Health and Human Services Secretary Richard S. Schweiker reportedly had questions about whether such a card would actually work and how it would be issued.

Forgeries of present Social Security cards are common among illegal immigrants in the Southwest, and there are those who think the practice would continue under any system.

Other elements of the proposed plan include a recommendation to prevent new influxes of Cuban or Haitian refugees by stopping boats on the high seas and detaining the would-be entrants.

The task force also has proposed amnesty for illegal immigrants already living in the United States and a guest worker program for future immigrants. If Reagan approves the recommendations, these guest workers would be issued the new national identity card.

After the cabinet meeting, Smith was told by a reporter that the Florida legislature was "getting impatient" for administration action on the refugee problem.

"We're doing everything we possibly can to come out with an overall program in a week or 10 days," Smith replied.

Reagan also met with visiting leaders of the National Association of Counties and used the occasion to lobby for his pending 25 percent, 33-month income tax cut bill. Passage, he told the county officials, "depends on your help."