President Reagan will sign the stopgap spending measure sent to him early today even though he has deep reservations about restrictions imposed by Congress on development of the MX missile, high administration officials said.

"It's the best we can get," said one official, who added that the MX would remain "largely on schedule" if Congress acts promptly in the spring.

These officials described Reagan, after listening to a day of back-and-forth debate among his top advisers, as believing he had salvaged as much as possible of his budget priorities from the lame-duck congressional session.

Reagan was said to be particularly happy over his success in using a veto threat to stop a Democratic-sponsored jobs bill he called a "pork barrel," and as generally pleased with the defense budget levels accepted by Congress.

But the president withheld any announcement of his decision yesterday in order to keep pressure on the Senate to complete approval of two measures that he regards as high priority -- the 5-cent-a-gallon gasoline tax increase and legislation allowing duty-free imports that is part of his Caribbean Basin initiative.

Reagan's decision came after a spirited battle among his advisers, some of whom shifted their own views during the day after a study of the language of the stopgap spending bill.

Early in the day, national security affairs adviser William P. Clark and Tom Reed, an NSC defense specialist, were described as favoring a veto of the bill because of its restrictions on MX development, its deletion of funds for the Pershing II missile pending successful testing and its inclusion of about $100 million more in aid to Israel than Reagan had requested. The MX was the major sticking point, according to administration sources.

But Reagan's political and domestic policy advisers, including chief of staff James A. Baker III, presidential assistant Richard Darman and legislative affairs director Kenneth M. Duberstein, favored signing of the measure. They reportedly argued that a veto would shut down the government over an issue that was less than clear-cut and that was unlikely to produce a result satisfactory to the administration.

The political advisers echoed the arguments made by Republican congressional leaders, who strongly favored a presidential signature on the stopgap bill.

The debate among Reagan's advisers began Sunday after a House-Senate conference committee deleted Reagan's proposal to spend $988 million to build the first five of the 100 nuclear-tipped missiles.

But an in-house analysis of the bill's language, which will permit $2.5 billion for MX research and development, and strong lobbying from pro-MX senators convinced Reagan that he should sign the measure, according to administration sources.

Ultimately, these arguments also convinced Clark and the NSC staff. They were described as displeased with the bill but unconvinced that anything better could be achieved from a Congress anxious to adjourn.

"Bad as the bill is from the MX point of view, there is no assurance we could do better after a veto," said one administration source.

When this official was asked if the $2.5. billion was "a fig leaf," he replied: "No, it's a face-saver and a time-buyer."

The administration view is that it will be easier to gain approval of MX funds next year after a commission that is expected to include the defense secretaries of past administrations makes a report to Congress on the MX-basing methods it prefers.

Foes of MX prevailed in the lame-duck session, administration analysts say, because they combined forces with members of Congress who favor the missile but could not accept the president's proposal to base the missiles in a "Dense Pack" system on an Air Force base in Wyoming.

Apart from the MX, the administration was prepared to describe the results of the lame-duck session as a victory.

Though the administration lost a number of proposals, including the Pershing funds, it was claiming success on big-ticket items such as the blocking of the jobs bill and was hopeful on the gas tax and Caribbean Basin initiative (CBI).

Reagan was waiting, an official said early last night, to see that "both the gas tax and the CBI landed on his desk."