Abstract: To solve the problem of low automation, low efficiency and certain dangerousness in the inspection of sonar transducer insulation, an automatic sonar transducer insulation tester is developed. In the tester, ARM is taken as the main control, the voltage comparison method and the full-bridge method are used for combined tests, the high-voltage circuit generates the high voltage required for measurement, and the gate control and serial port are used to achieve automation and remote control of measuring path. Therefore, the measurement automation is realized and the efficiency of equipment maintenance and support is improved.