The invention discloses an emergency power supply automatic switch-in device, which relates to the technical field of electricity grids. By means of introducing a pair of input quantities reflecting position of a 1DL circuit breaker, a failed-to-act phenomenon of the automatic switch-in device is solved; by means of introducing a second group of voltage, a misoperation phenomenon of the automatic switch-in device is solved; structure is simple, adding a set of emergency power supply switch-in device in addition is avoided, doubling functions are realized on one set of emergency power supply automatic switch-in device, problems of misoperation and failed-to-act phenomenon of the emergency power supply switch-in device are solved effectively, time and labor are saved, and working efficiency is improved.