The invention discloses a tailoring device used for a PV piece, and relates to the technical field of plastic machining. The device comprises a bottom plate, two sliding grooves are formed in the upper surface of the bottom plate, the two sliding grooves are formed in the left side and the right side of the upper surface of the bottom plate correspondingly, sliding blocks are in sliding connectioninto the sliding grooves, a sliding device is fcixedly connected to the upper surfaces of the sliding blocks, one end of the front face of the sliding device and one end of the back face of the sliding device are fixedly connected with baffles, and the lower surfaces of the two baffles are fixedly connected to the upper surface of the bottom plate. According to the tailoring device used for the PV piece, the sliding device, a second sliding rod, a second sliding sleeve, a nut, a screw, a third sliding rod, a third sliding sleeve and a blade are arranged, the blade can tailors the PV piece directly, compared with manual tailoring, the straight-line tailoring standard is mastered, the condition that the tailoring path deviates is avoided, the tailoring effect of the PV piece is ensured, andconvenience is brought to tailoring of PV piece.