Abstract: To solve the disadvantage of slow action of existing feed protection switches, a leakage detection device for mine power supply network based on dual-controller was designed.The device takes ATmega329 single-chip microcomputer as control core to realize functions of fault judgment and control,adopts ATT7022 DSP to realize functions of AC signal collection and statistical calculation,so as to process functions of data processing and control dividually,which improves fault processing speed of the device and accuracy of data collection of AC signal effectively.Its selective leakage detection circuit adopts self-adjusting and self-adapting function design so that it has better adaptability to different mine environment.Commissioning result showed that the device has high precision,quick action speed and strong adaptability.