The invention relates to the technical field of equipment for preparing mortar and mortar mixing materials, particularly to a mortar stirring machine. The mortar stirring machine comprises a motor, astirring barrel and a stirring paddle, wherein an output shaft of the motor is connected with the stirring paddle; the stirring barrel comprises a fixed barrel and a rotating barrel positioned in thefixed barrel; the stirring paddle is positioned in the rotating barrel; pawls are arranged on the stirring paddle; a ratchet ring matched with the pawls is arranged at the top of the rotating barrel;a grinding disc is arranged at the bottom of the rotating barrel; a feed inlet is formed in the top of the fixed barrel; a grinding chamber and a discharge opening which communicates with the grindingchamber are arranged at the bottom of the fixed barrel; the grinding disc is rotatably arranged in the grinding chamber; a communication hole which communicates with the grinding chamber and the interior of the rotating barrel is formed in the grinding disc; a control gate used for closing the discharge opening is arranged at the bottom of the discharge opening; and moving blocks used for intermittently opening the control gate are arranged on the grinding disc. Through the scheme, the situation that caked materials are generated or the discharge opening is blocked during the discharge process of mortar can be effectively prevented, and quality of output mortar is improved.