Aiming at the complexity of the failure rate variety in weapon usage, a failure rate prediction method using a grey linear regression model (GM) is proposed. The model uses the sum of the linear regression equation and exponential equation to fit the failure rate curve. The deficiency caused by the lack of an exponential growth trend in the linear regression equation and the lack of linear factors in GM (1,1) can be improved. According to the analysis and prediction of the spare equipment, the results show that the grey linear regression model is superior to both the individual GM model and the linear regression model in the prediction accuracy of the failure rate. Moreover, the historical data does not require a typical distribution. The prediction results of the model can thus be regarded as the decision making basis for equipment maintenance.