The invention relates to the technical field of pet equipment and discloses device for cat excretion. The device comprises a box, a screening mechanism, a cat door, an induction switch, a first electromagnet, a latch mechanism and a control module, wherein the box is provided with a cat litter cavity, an accommodating cavity, a first opening, a first storage cavity and a second storage cavity; the screening mechanism comprises a first motor, a second motor, a swing rod, a screw, a slider, a frame, a fixing rod, a first slide guide rod, a second slide guide rod, a plurality of first slide rings, a plurality of second slide rings and a screen, the first motor is fixedly mounted on the box, and the rotation axis of the first motor is vertical to the extension direction of the cat litter cavity and is coaxial with the central axis of a retaining wall. The device has the advantages that the first motor, a second motor, a drive machine and the like are controlled through the control module, excrement in the cat litter cavity can be screened out and collected in the collecting box, automatic collecting of the excrement in cat litter is achieved, and the device is quite convenient to use.