The invention discloses a photoelectric door lock reminding device. The device comprises a door cover side frame, a transverse light ray emitter, a permanent magnet, a clamping lock, a door side frame, a key inserting port and a lock cylinder, wherein a longitudinal light ray emitter is mounted at the lower end of a single-chip microcomputer, and a light ray through hole is formed in the lower part of the longitudinal light ray emitter; the transverse light ray emitter is mounted at the right side of the single-chip microcomputer, and screw cap fixing holes are formed in two sides of the transverse light ray emitter; the permanent magnet is mounted at the left side of the single-chip microcomputer, and a loudspeaker is mounted on the upper surface of the single-chip microcomputer; the clamping lock is mounted at the lower end of an alarming reminding device; a signal receiver of which the lower part is provided with the key inserting port is mounted in the door side frame. According to the photoelectric door lock reminding device, the photoelectric signals are converted, and the corresponding signals are handled through the single-chip microcomputer, then the loudspeaker is controlled to make different sounds to remind a user whether a door is safely locked, and thus the safety of the door lock is improved.