The invention provides a large-drift-diameter high-pressure rotation joint used for a drilling machine. The large-drift-diameter high-pressure rotation joint used for the drilling machine comprises a mull-coupling nut, a first O-shaped ring, a connecting pipe, a gland joint, a main shaft, a first pad, a retainer ring, a clamping key, a second pad, a shell, a lower cover, a first oil seal, a first bearing, a second bearing, a third bearing, a second oil seal, a third O-shaped ring, a compression ring, a V-shaped ring and a supporting ring. The supporting ring, the V-shaped ring and the compression ring are sequentially compressed into an inner stage of one joint end of the gland joint. The second oil seal is compressed into the first pad. The first oil seal is compressed into the lower cover. The first bearing, the second pad, the second bearing, the clamping key, the retainer ring, the third bearing and the first pad are sequentially arranged on the main shaft in a sleeving mode. The clamping key is clamped into a key groove formed in the surface of the main shaft. The main shaft is riveted into the shell. The supporting ring, the V-shaped ring and the compression ring are arranged at one end of the main shaft in a sleeving mode. One end of the shell is connected with and fastened to one joint end of the gland joint. The throughput is increased since the sealing positions are ingeniously and reasonably arranged.