To provide a method and device of high-efficiency operation for controlling a pusher so as to obtain a higher processing speed in a region where an overload is not applied in a uniaxial crusher.

The operation control method and device of the pusher is used in the uniaxial crusher that crushes material 11 to be crushed supplied by the pusher 3 driven by a hydraulic cylinder 5 to a rotor 1 having a number of blades attached onto the circumference and rotating. The operation control method includes the steps of: prestoring a function relating to the speed of the pusher 3 that has a correspondence value predetermined in accordance with the load of the rotor 1; estimating the load of the rotor 1; calculating the speed of the pusher 3 corresponding to the load of the rotor 1 according to the stored function; adjusting the amount of a hydraulic fluid fed to the hydraulic cylinder 5 so as to correspond to the speed of the pusher 3; and controlling the speed of the pusher 3 by feeding the hydraulic fluid.