Attorney General Benjamin R. Civiletti defended the Carter administration's handling of the Cuban-Haitian refugee crisis at a Senate hearing yesterday, but admitted there's no real way to stop the continuing 200-a-day flow from the Caribbean to Florida.

Several members of the Senate Judiciary Committee had sharp questions for Civiletti and other administration witnesses, most notably Sen. Thad Cochran (R-Miss.) who said the record of dealing with the 130,000 new immigrants showed a "total breakdown in leadership."

"Is there some limit to our hospitality?" he said. "How many is too many?"

Civiletti replied that the Navy and Coast Guard couldn't absolutely control the entire Florida peninsula and straits "unless we want to be a police state."

Almost 9,000 Cubans and 4,300 Haitians have arrived in the United States since June 19, when the administration announced a new immigration parole status for the first influx.

Civiletti and Victor Palmieri, the State Department's coordinator for refugee affairs, had difficulty explaining how the arrivals since June 19 have been treated differently.

Just Thursday, the White House buckled under political pressure from the congressional delegation in Florida and agreed to full federal financing of benefits for the pre-June 19 group. The original plan was 75 percent federal funding of some benefits.

Sen. Strom Thurmond (R-S.C.), the ranking minority member of the committee, said the financial drain on the United States in accepting and resettling the Haitians and Cubans amounted to "backdoor foreign aid" to Cuban President Fidel Castro.

Sen. Howard Metzenbaum (D-Ohio), said he was concerned about reports of "squalid" conditions at a south Florida camp for newly arrived Haitians. He quoted a volunteer agency expert as saying the camp was worse than any he's seen for Indochinese refugees in Southeast Asia.

Committee Chairman Edward M. Kennedy (D-Mass.), who was a constant critic of the administration program last spring when he opposed President Carter in the Democratic presidential primaries, refrained from the general verbal assault.

The hearing was scheduled as a required "consultation" with Congress about the expected flow of refugees into the United States for the fiscal year that starts Oct. 1.

Civiletti said the country would take in 217,000 refugees this year, 14,000 fewer than in the current fiscal year. Of these, 168,000 are expected to be Indochinese refugees, he said.

The committee's attention, however, turned quickly to the continuing problems of dealing with the newcomers that the administration treats as, but refuses to call, "refugees," in the legal sense.

About 11,000 Cubans are still awaiting resettlement at camps in Arkansas, Wisconsin and Pennsylvania. As part of its agreement to placate state officials in Florida, the administration has agreed to shut down all camps there.

The problem, Palmieri said yesterday, is that the newcomers don't want to leave south Florida and other locales don't want resettlement centers in the neighborhoods.

Civiletti said the administration is still taking a hard-line law enforcement attitude against those who tried to profit from the spring's flotilla across the Florida Straits from Mariel, Cuba.

A team of 18 prosecutors has been assembled in Miami to handle the hundreds of cases, he said, and federal investigators are beginning to investigate possible criminal conspiracies that supply the financing for the continued illegal traffic from Cuba.

Palmieri said the administration's sudden switch to officially supporting 100 percent funding for Cuban-Haitian benefits was caused by the "drastic fiscal impact" in south Florida, not Florida's status as a key presidential election state, as Cochran suggested.

Originally the administration asked for less funding because of concerns about the impact on the budget, Palmieri said.

In answer to a question by Sen. Alan Simpson (R-Wyo.), Civiletti explained that 1,800 hardened Cuban criminals who won't be admitted to the United States will be imprisoned until Castro or someone else agrees to take them in. In the meantime they are being held in prisons at a cost of $8,000 to $12,000 a year each.

Kennedy ended the hearing with his persistent suggestion that the administration work to internationalize the problem to put pressure on Castro and share the burden. So far only 88 Cuban refugees have been resettled in countries outside the United States.