The invention relates to the technical field of corn grinding, and discloses a corn crushing and grinding device. The device comprises a shell, a feeding hopper, a quantifying assembly, a crushing assembly, a grinding assembly, an opening and closing assembly, a screening assembly, a conveying assembly, a workbench and a loading box, wherein the shell is arranged at the top end of the workbench, the feeding hopper is arranged at the top end of the shell, the quantifying assembly is arranged at the top end of the shell, the crushing assembly is arranged inside the shell, the grinding assembly is arranged in the shell, the opening and closing assembly is arranged below the crushing assembly and located beside the grinding assembly, the screening assembly is arranged below the opening and closing assembly, the conveying assembly is arranged at the top end of the workbench, the workbench is arranged at the lower end of the shell and the loading box is arranged in the shell. By means of thedevice, the situation that the corn processing efficiency is affected due to the fact that a feeding port is prone to being blocked when too much corn is poured into during feeding, and the corn grinding quality is affected due to the fact that existing equipment does not grind corn thoroughly during corn grinding is avoided.