A two wire infrared photoelectric sensor frequency measuring system based on NRF24L01 wireless communication is designed. In order to reduce the number of wires used in three-wire sensor and improve the stability of signal, a two-wire photoelectric sensor is designed. In the design process, the improved two-wire sensor circuit is designed after the in-depth study of the three-wire sensor circuit, and then the signal processing circuit is designed to convert the pulse signal of the sensor into frequency signal, which is transmitted to the wireless transmission module through RS-485 bus, and finally transmitted to wireless communication. The receiving module finally displays the measured data through the host computer software. It is proved by experiments that it can collect signals in a stable and accurate manner. After comparing the data obtained by the two sensors, it is concluded that the data measured by the two-wire sensor is more stable, less fluctuation, and only two lines are needed to achieve the purpose of the experiment.