Sensor for detecting door lock state

The invention discloses a sensor detecting a door lock state. The sensor comprises an optical coupler and a conducting plate, wherein one end of the light emitting diode of the optical coupler is grounded, and the other end of the light emitting diode is connected with a power supply; the emitter of the photosensitive transistor of the optical coupler is grounded, and the collector of the photosensitive transistor has two branches, one of the branches is connected with the power supply, and the other branch serving as a signal output end is connected with a main control board; and the conducting plate is serially connected with the branch, connected with the power supply, of the collector of the photosensitive transistor so as to block off at least the side surface of the optical coupler in the baffle insertion direction. The sensor can be used for intelligently and accurately detecting the door lock state, and can well ensure the safety operation of a centrifuge.