The corn thresher operates in axial flow driving mode and has axial flow force produced by the spike teeth fixed onto the surface of cylinder and in some angle to the cylinder radial direction. The threshing mechanism consists of feeding bin, main cylinder shaft, subsidiary cylinder shaft, pushing unit, raising unit, slag remover, clutch port pulling rod assembly, frame, clutch, clutch elbow wall, cylinder sieve, spike teeth, slag throwing board and transmission mechanism. Partial spike teeth are fixed onto the surface of the main cylinder shaft, perpendicular to the axis of the main cylinder shaft and has a radial deflection angle of 5-10 deg, and other spike teeth are fixed onto the surface of the subsidiary cylinder shaft, perpendicular to the axis of the subsidiary cylinder shaft and has a radial deflection angle of 5-10 deg. The corn thresher has high threshing performance and high threshing efficiency.