In order to ensure the normal operation of the power supply module of the aircraft information processing equipment, The typical BUCK step-down circuit is simulated by Simulink to simulate the degradation process of capacitance and inductance, and the fault characteristic parameters of power supply module are determined by combining the degradation model of capacitance and inductance theory; Analyze the modeling process of grey model, From the data preprocessing and the dimension of training data, an adaptive gray model of data smoothing preprocessing is obtained; Measuring the ripple voltage of power supply of information processing equipment at equal time intervals. The GM (1,1) model, metabolism model and improved grey model are used for comparative analysis. The validity and correctness of the improved grey model are verified by using the average relative residual as the criterion of prediction accuracy.