The invention discloses an industrial grinder rotating gear device. The structure of the industrial grinder rotating gear device comprises a gear, wherein a shaft hole is formed in the middle of the gear, a octagonal concave circular groove is formed in one side surface of the gear, a octagonal thin disc is arranged in the concave circular groove, a disc is arranged above the thin disc, a convex cylinder is arranged in the middle of the disc, and a separable spring and a nut are arranged on the convex cylinder. As the gear is connected with the octagonal thin disc and the disc, a plurality of friction surfaces exist, and as a result, large power and torque can be transferred. At the same time, the industrial grinder rotating gear device is favorable to protecting the gear from damage, prolongs the service life of the gear to a certain degree, and improves the work stability.