A hydrogen bomb buried in a boxcar-size canister was detonated in the Nevada desert today in a test of technology for President Reagan's Strategic Defense Initiative (SDI), often called "Star Wars."

An Energy Department spokesman said there were no problems during the test and "no information of any major ground movement off the test site."

Department officials declined to discuss the purpose of the test, but Defense Department and congressional officials said earlier that it was designed to test the concept of harnessing X-rays produced by a nuclear explosion into a laser cannon to destroy Soviet missiles.

The blast 100 miles northwest of Las Vegas registered 5.6 on the Richter scale, according to John Minsch of the National Earthquake Information Center in Boulder, Colo. It measured 5.3 at California Institute of Technology in Pasadena.

Las Vegas Metropolitan Police said there was no ground movement in the city.

The nuclear explosive was buried in a shaft 1,800 feet below the desert floor at Pahute Mesa. The Lawrence Livermore National Laboratory test, code-named "Goldstone," had an explosive force of 20 to 150 kilotons, the Energy Department spokesman said.

The test had been postponed several times since Dec. 19 because of unfavorable winds and the Christmas holiday. Scientists routinely delay underground nuclear tests here when winds are blowing toward the south and west because of the danger that an accident could produce a radioactive cloud that might drift over a populated area.