Sand screening machine

The utility model relates to a sand screening machine which comprises a machine frame, an outer cylinder is arranged in the machine frame through a supporting piece, an inner cylinder is arranged in the outer cylinder in a rotating mode, the middle of the front end of the inner cylinder protrudes forwards to form a feeding pipe, multiple circles of spiral blades are fixed to the inner wall of the inner cylinder, and a discharging pipe is fixed to the rear side of the bottom of the outer cylinder. And a rotating structure for driving the inner cylinder to rotate is arranged on the outer cylinder. Sand enters the inner barrel from the outer barrel through the feeding pipe, the inner barrel is in a net shape, and the rotating structure can drive the inner barrel to rotate, so that material flow can be continuously subjected to roller screening for multiple times among the multiple circles of spiral blades in the inner barrel, and the sand repeatedly rolls and slides to be fully dispersed and separated; fine sand