The invention discloses a hopper device of a steel ball sorting machine. The hopper device of the steel ball sorting machine comprises a hopper disc and a steel ball distributing device. The steel ball distributing device comprises a base, a ball separating column, a driving component and a reciprocating pushing component, wherein the ball separating column can be driven to rotate and move in reciprocation via the driving component and the reciprocating pushing component, a plurality of annular grooves are reserved on the column surface of the ball separating column, a plurality of separating bars are allocated on the ball separating column, the annular grooves are separated by the separating bars into a plurality of loading grooves corresponding to steel balls, the steel balls fall from the hopper disc to the loading grooves on the ball separating column, via reciprocating transitional ball collecting of the ball separating column, quantities of the steel balls in the loading grooves are equal, and meanwhile, the ball separating column rotates to feed the steel balls to a discharging port at the lower end of the base. The hopper device of the steel ball sorting machine is capable of uniformly distributing the steel balls and wide in application range, since the hopper disc does not vibrate, the hopper device is low in noise, small in steel ball abrasion, high in reliability, large in capacity of the hopper disc, and low in driving power since only the ball separating column needs to be driven to rotate and slide in reciprocation during feeding.