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 magnetoresistive switch to wake up is proposed. The method uses a domestic master controller HC32L072FAUA to accomplish various tasks; uses magnetoresistive switches to trigger the microcontroller in the sleep state; uses switching circuits to allow free switching between the external power supply and the lithium battery power supply; and uses voltage source detection circuits and lithium battery power detection circuits to ensure that the circuits work properly. The experiments show that the combination of the deep sleep mode of the microcontroller and the wake-up triggered by the magnetoresistive 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.