According to the analysis of the sum of squared residuals (SSE), this paper have defined the discriminant function and SSE change rate and discussed the discrimination standards and parameter calculation method of weighted forecasting model. Based on the balance of overall SSE and partial SSE, the parameters and forecasting model can be calculated by the value scope of SSE change rate. Through the discriminant and analysis of the mining safety incident weighted forecasting model, the derived model can have a high recent forecasting accuracy, thus it can provide reliable basis for safety management decision making. Discriminant function and SSE change rate have extensive applicability and can be used as a discrimination standard of the security system prediction model.