The Senate last night unanimously approved the most sweeping revision of the nation's military since 1947, in an effort to give field commanders more authority and to quell interservice rivalries.

Sen. Barry Goldwater (R-Ariz.), chairman of the Armed Services Committee, who became visibly emotional when the measure was named after him, said after the unanimous vote that the reform effort was his proudest achievement as "an old soldier" and a lawmaker with 30 years in the Senate.

"It's the only . . . damned thing I've done in the Senate that's worth a damn," Goldwater, who is retiring from the Senate, said. The whole purpose of the bill, which now goes to the House, is "to make a better fighting force out of the military."

The measure would give U.S. theater commanders, such as those in charge of the Atlantic and Pacific regions, considerably more authority than they have today. The commanders would have the authority to train and supervise the activities of deputies, regardless of whether they came from the Army, Navy, Air Force or Marine Corps. The commanders also would have a voice in who was selected for those deputy jobs and in directing their day-to-day activities.

Under the current system, theater commanders often cannot control the "component commanders" beneath them who report to superiors in Washington through a separate chain of command.

The Senate bill also is designed to end the consensus approach to decisions made by the Joint Chiefs of Staff, the nation's highest military body comprised of the four service chiefs and a chairman. The chairman no longer would be obliged to reach unanimous agreement among the heads of the Army, Navy, Air Force and Marine Corps before making a recommendation to the president. Instead, the chairman would be the military adviser to the president with authority to state his position on any issue, regardless of whether the rest of the chiefs agreed with him.

The Senate Armed Services Committee also had set out to reform the procurement system at the Defense Department in response to horror stories about inefficient weapons buying. But in hammering out the final bill last night, the Senate left hanging several questions on the issue.

The Senate approved the establishment of a weapons "czar" to oversee procurement with the title of undersecretary of defense for acquisition; it also approved a second undersecretary without specifying its functions. Goldwater said those details will be worked out in a House-Senate conference searching for a compromise on competing reform measures.

The House already has voted for a revision of the Joint Chiefs along the lines proposed in the Senate bill. However, a series of other Pentagon changes are embodied in a separate measure, which is expected to be added to the fiscal 1987 procurement bill. That bill is not expected to be passed until next month, according to House officials.

Sen. Sam Nunn (Ga.), ranking Democrat on the Armed Services Committee, predicted that it would take "five to 10 years" for the military to implement all the changes embodied in the Senate-passed bill, if it becomes law. He said one objective of the changes is to "give authority and incentive" to military leaders to think as one service when it comes to planning military strategy, tactics and budgets. He said that the idea is to take those responsibilities from Pentagon bureaucrats and give them to the leaders in the field