A number of military retirees working on Capitol Hill as special experts have a larger income from the government - a combination of pension and pay - than the $57,500 salary of the members of Congress who hired them.

Although nobody has solid figures, congressional sources estimate that at least 150 Senate and House aides, thanks to a waiver of a law imposed by Congress on the rest of government, make some of the top salaries in government. Some get more than the majority and minority leaders of the Senate and the speaker of the House. One or two workers are believed to earn more than the $75,000 salary of the Vice President.

The 535 members of Congress have more than 18,000 employes who are exempt from many of the laws relating to wages job security and working hours that Congress imposes on the rest of the government and many private employers.

Most of the 141,000 military retirees working for the government are exenlisted personnel, or reserve officers. By law, both groups are allowed to keep full pension plus their civil service salary.

But retired regular officers, in most cases, must rake sharply reduced pensions when they are hired by the federal civilian government because of the Dual Compensation Act. It limits them to drawing the first $4,219 of their retired pay plus one half the remainder.

Congress did, however, provide a legal loophole to the pension restricting law. The idea was to permit certain federal agencies to hire retired generals, admirals and other high-ranking regulars with special skills and entice them with promises of full pay and pension.

It appears that one of the primary users of the special exemption from the dual pay law is the Congress itself.

Last month this column reported that the National Aeronautics and Space Administration had dozens of top-level military retirees earning upwards of $78,000 a year. NASA now says it has at least 23 employees with "taxable" pay and pension incomes exceeding the $57,500 rate of pay for members of Congress.

House payroll experts, at the behest of Speaker Thomas P. O'Neill (D-Mass.) are now checking to find out how many super-salaried employees it has, and why they were given exemptions supposed to be limited to retirees with exceptional skills not available from any other source.

In the House, the speaker has authority to exempt new employes from the Dual Compensation Law. Aides say that O'Neill has been following a "very hard line" in interpreting the exemptions, and has approved few, if any, since taking office. His predecessor, Carl Albert, was much more generous with the exemptions, sources say, providing them almost automatically as a "courtesy" to colleagues who wanted to hire regular military retirees and give them maximum pay and pension benefits.

On the Senate side, Vice President Mondale has the authority to grant waivers from the dual pay act. Aides say that Mondale has continued the "hard line" approach adopted several years ago and that he has approved few if any special hirings since taking over.

New House rules will make it less attractive for members in the future even to ask for exemptions. The rules will require that the member pay - out of his own office salary kitty - for pay differnetials granted military retirees. Meantime, O'Neill is being "very tough" aides say, and some believe the day of Congress' waiver of its own rules - in this instance anyhow - may be almost over.