Abstract: In order to solve the problems of losing angle data when the automatic fire gun is accidentally powered down and using a backup battery to keep the angle power supply for a short period of time, a cooperative method utilizing the deep sleep mode of the microcontroller and the magneto resistive switch to wake up is proposed. The method uses a domestic master controller HC32L072FAUA to accomplish various tasks. The magneto resistive switches is employed to trigger the microcontroller in the sleep state. The switching circuits is utilized to allow free switching between the external power supply and the lithium battery power supply.The voltage source detection circuits and lithium battery power detection circuits are used to ensure that the circuits work properly. The experiments results show that the combination of the deep sleep mode of the microcontroller and the wake-up triggered by the magneto resistive switch allows the automatic fire gun angle position detection system to memorize and update the angle data, and the design makes the automatic fire gun angle position detection system more suitable for long-time work under the harsh conditions such as accidental power failure.