Abstract: The shortcoming of the present magnetic particle testing instrument was analyzed, and the rechargeable and programcontrolled magnetic particle testing instrument was designed, which was on the basis of battery, microcomputer controlled, liquid crystal display with Chinese character and PWM(pulsewidth modulation) regulated. The power could be adjusted automatically during working course, and also could be regulated manually. The instrument was tested and shown that it could reveal the A115/100 clearly, and could work continuously for more than 5 hours once charged. The results showed that the device could meet the need of magnetic particle testing completely.