The utility model discloses a coal slime tailing ash content measuring device based on machine vision, and is suitable for the field of coal detection. The device comprises a measuring box and a single-chip microcomputer, the measuring box is of an opaque cuboid structure. Baffle is arranged in the middle of the measuring box, the baffle divides the interior of the measuring box into a front spaceand a rear space; an opening for connecting the front part and the rear part is reserved below the baffle; wherein a cleaning device and a slime water collecting device are arranged in the front halfspace of the measuring box; an information acquisition device is arranged at the top in the rear half space of the measuring box, a stirrer is arranged at the bottom of the front half space of the measuring box, a floating ball liquid level meter is arranged at the position, close to the baffle, of the rear half space of the measuring box from top to bottom, and a drainage device is arranged at the tail of the rear half space of the measuring box; the structure is simple and the measurement effect is good.