Abstract: A solid material grinding method and device with an adjustable discharge size includes a grinding disc housing, and a movable grinding disc and a stationary grinding disc provided in a grinding disc cavity of the grinding disc housing coaxially with grinding surfaces opposite to each other. The movable grinding disc is driven to rotate in the grinding disc housing, thereby grinding materials between the movable grinding disc and the stationary grinding disc. The movable grinding disc is further connected to a pushing mechanism, and the pushing mechanism adjusts the distance between the movable grinding disc and the stationary grinding disc in a push-and-pull manner. A top rectifying blower and a side edge rectifying blower respectively blow gas from an upward side and a lateral side of the movable grinding disc and the stationary grinding disc. A central rectifying blower blows gas to the center of the stationary grinding disc.