SANTA BARBARA, CALIF., NOV. 27 -- The new treaty to eliminate mid-range superpower nuclear missiles would not totally protect against Soviet cheating, but the treaty and its verification measures remove any military incentives for the Soviets secretly to rebuild their arsenal, a senior administration official said today.

The official, who accompanied Secretary of State George P. Shultz to Geneva this week, spoke to reporters here about the treaty's verification measures as President Reagan prepares to sign the document at the Dec. 8-10 summit with Soviet leader Mikhail Gorbachev.

The official, who has daily contact with the president on national security matters and met with Reagan at his mountain ranch this week, spoke on condition he not be identified. He urged conservative critics of the deal to "hold their fire" so the arms agreement can be explained by the administration over the next few weeks.

The official acknowledged that the Soviets "can always cheat" despite the provisions of the treaty allowing the United States and the Soviets to send teams to each other's countries for 13 years for inspections of some missile-production facilities. But, he asserted, "What we're trying to make sure is that we remove as much incentive as we possibly can for them to cheat, and if they yet persist in wanting to cheat, or trying to cheat, they will gain no military significance from it."

The official described how, under the proposed treaty, U.S. and Soviet inspectors could demand to see missile facilities within nine hours. This is "a very limited amount of time to hide anything or call in Bekins Van Lines," he said. The treaty calls for the mid-range missiles to be destroyed over a three-year period and provides for 10 years of inspections by each side of facilities in the other country.

{Meanwhile, Senate Republican Leader Robert J. Dole (Kan.) said after a briefing by Shultz in Washington that he wants to see all the accord's details before he decides whether to support it, The Associated Press reported.

{"I was pleased with the outline of verification procedures the secretary presented," Dole said. "But I want to see all the details before I am satisfied with the crucial treaty component."}

Reagan long has made Soviet treaty violations a centerpiece of his complaints about Moscow's military policies. He has accused the Soviets of violating both the 1972 Antiballistic Missile Treaty and the unratified limits set by the 1979 SALT II treaty. But the senior official said the new intermediate nuclear forces treaty is different from previous agreements because the Soviets have already made the military calculation to give up their mid-range missiles.

"What incentive would they have to cheat, having given up this large number of missiles and recognize that they can afford to live without this large number of missiles?" he asked. "In other words, they have made the military calculation that they can afford to live without that large number of missiles. Is there incentive for them to squirrel away 100 here and 100 there that they will have difficulty exercising? They can't test them to make sure the reliability of the missiles. Is there an incentive for them to do it?

"I think probably not. But I'm not relying on whether there is incentive or not. Assuming that they might do that, then the question you have to ask yourself is, is that a significant threat to us, and should we be terribly concerned if they keep 100 here and there?

"I would say, yes, we should be terribly concerned, but in terms of it presenting a significant military threat to us, I think the answer to that would be probably not. All we would have to do is see one of those missiles any time and we have a treaty violation. So I have a hard time conjuring up a political incentive . . . {or} any military incentive that they might have to put themselves in that position."

The official also noted that the Soviets are still building their force of SS25 missiles, which are capable of being aimed at the same targets covered by the older SS20 missiles being destroyed under the treaty.

"It is always possible for cheating to take place, and we recognize that," the official said. "But we think we've got a pretty good system in which we watch the visible force structure disappear in three years."

The official noted that the United States retains its satellites and other "national technical means" to monitor whether the Soviets test a missile prohibited by the treaty. Any violations would be reported to a verification commission, and if the United States was dissatisfied with Soviet compliance, it could always abrogate the agreement, he said.