The invention relates to the technical field of maize processing and discloses a maize threshing machine. The maize threshing machine comprises a worktable, an air cylinder and a first speed reducing motor. The air cylinder comprises a piston rod, the upper end of the worktable is rotatably connected to a spline shaft, an upper key of the spline shaft is connected to a shaft sleeve, the shaft sleeve and the piston rod are locked, a first supporting rod and a second supporting rod are fixedly connected to the shaft sleeve, a first gear is arranged on the first supporting rod, and a slicer is arranged on the first gear. The slicer comprises two slicing panels, an included angle is arranged between the two sliding panels, a spring is connected between the two sliding panels, the end, far from a column, of the second supporting column is rotatably connected to a second gear, the second gear is fixedly connected to a hanging barrel, a through hole is formed in the hanging barrel, a core column which is coaxial with the hanging barrel is arranged in the hanging barrel, a lifting hook is arranged on the core column, a socket and a friction plate are also arranged on the worktable, and a second speed reducing motor and a third gear are arranged above the friction plate. According to the maize threshing machine provided by the invention, relatively intact shapes of niblets which are threshed are kept, so that the processing quality of the niblets is enhanced.