The invention discloses a gapless numerical control index rotary table structure for a cam roller. The gapless numerical control index rotary table structure comprises a box body, a cam input shaft, a tower type output shaft, a rolling pin bearing, a conical bearing, a deep groove ball bearing, a first gear, a second gear, a brake servo motor, a rotary working table, locking nuts, an eccentric bearing pedestal, a spacer ring, a gear box, an eccentric ring, a cover plate, a metal plate protection cover, a cable box, an oil immersion lens, window covering parts, oil hole screws, bolts, an oil seal and a seal ring. By means of the numerical control index rotary table structure for a numerical machining center, a transmission gap inside a rotary table is eliminated, and accuracy of machined workpieces and rotation stability of the rotary table are improved; high-speed running and machining can be achieved through a cam roller transmission structure; no brake device needs to be arranged in the index rotary table, braking is conducted in the index positioning and machining process through the brake servo motor, external hydraulic stations are reduced, cost is greatly reduced, and energy is saved; and the output shaft is arranged on the outer round wall of a shaft through the large bearings, and the loading capacity of the rotary table is enhanced as well.