Abstract: The medium and low voltage distribution networks with voltage levels of 35kV and below have a large number of equipment, complex operation conditions, and difficulty in fault location. In order to improve the location accuracy of the distribution network faults by the portable fault recorder and ensure the shortest detection path, a polymorphic recorder is proposed. Adaptive optimization method of portable disturbance recorder in mode. According to the working theory of the portable fault recorder, the multi-state recording mode of the device is determined. According to the substation fault data recorded in the transient recording mode and the steady-state recording mode, the polymorphic association mining method is used to mine the devices existing in the recorded data to locate the substation fault. Accuracy affects the parameters, get four adaptive optimization parameters of the device, take them as the four unknown functions in the least squares support vector machine, calculate the adaptive optimization function values ​​of the four parameters of the wave device, and apply the calculated values ​​to the portable device. In the fault recorder, the adaptive optimization of the portable fault recorder is completed. The example analysis results show that after the optimization of this method, the voltage waveform of the distribution network recorded by the portable fault recorder at some monitoring points fluctuates violently, and the fault detection effect is better, which reflects the self-adaptive optimization effect. The maximum value of the modulus of , constitutes three sets of positioning results. When the path between the two detection points is the shortest, an accurate distribution network fault location result can be obtained.