The Chinese divers held the top two spots after both the preliminaries and the semifinals, and it was more of the same in the finals.
Xie broke down in tears when the scores for his final dive were posted, a string of 9.0s and 9.5s that clinched the victory with 558.75 points. Wang came over to give his teammate a hug.
The biggest drama was for the silver, but Wang nailed his final dive to finish with 534.90 and hold off Jack Laugher of Britain.
Laughter was only 2.05 points behind Wang going to the final round but over-rotated his entry a bit on his highest-difficulty dive, a forward 2 1/2 somersaults with three twists. The telltale splash left him with 518.00 points and the bronze.
Laugher has won a medal on the springboard at the last two Olympics, having claimed a silver at the 2016 Rio de Janeiro Games.
Long the world's dominant diving nation, China has been near-perfect at the Tokyo Aquatics Centre with five gold medals in six events.
The only slip came in men's 10-meter synchronized, where Chen Aisen ad Cao Yuan settled for silver in an upset win by the British team of Tom Daley and Matty Lee.
Otherwise, the Chinese have captured every medal available to them. They won the other three synchronized events and have gone 1-2 in the first two individual events of the games.
Xie and Wang added to the gold they won in 3-mter synchronized.
The most touching moment came when Ken Terauchi of Japan, just four days shy of his 41st birthday, completed the final dive of his sixth Olympics.
He failed to win Japan's first diving medal ever, finishing last in the 12-man final. Still, Terauchi received a standing ovation for all the coaches and competitors in the nearly empty arena and posed for pictures afterward with everyone who wanted one.
The Americans were hoping to claim their fourth medal of the Tokyo Games, which would match their best output since 1988. But Andrew Capobianco, a silver medalist in 3-meter synchro, finished 10th.