The invention discloses a sludge chopping device, which comprises a support plate, a lower grid, a guide rod, an upper grid, a bracket, a power mechanism, a rotating shaft, a cam, a slide plate, a guide wheel, a connecting plate, a reset mechanism, a position limiting When the sludge falls on the upper grid, the power mechanism drives the cam to rotate through the rotating shaft, thereby pushing the sliding plate fixedly connected with the guide wheel to slide, and then drives the upper grid to move along the guide rod. When the sliding plate moves to the left , the spring is compressed, and when the cam reaches the maximum stroke, it starts to return, and the spring returns to push the slide plate to move to the right in the return stroke, so that the upper grid can move back and forth linearly along the guide rod, and the lower grid and the horizontal and vertical blades set on the upper grid can be Under the combined action, the sludge is chopped horizontally and vertically. The structure of the device is simple, the upper grid can automatically reciprocate, and the sludge is chopped horizontally and vertically under the joint action of the upper grid and the lower grid. It not only has a high degree of automation, but also cuts the sludge evenly, continuously and quickly. .