Abstract: In Wangjiazhai Coal Mine,the discharge is mainly controlled by precipitation.In order to predict discharge,discharge series and precipitation series are used to establish immediate discharge nonlinear predicting model.By the mutual relation analysis between the discharge series and the precipitation series,the discharge is 0～1 month later than the precipitation.Applying the time series blend threshold autoregression model,the immediate discharge nonliner predicing model Tarso2,（1,1）,（1,1） is established.The discharge in 1991 is predicted,and the error ratio is 10%～20%,which meet the requirements of mining.Not only the selfrelation of discharge,but also the mutual relation between the discharge and the precipitiation is considered in the model,it is applicable to the coal mines in the South of China in which discharge is controlled by precipitation.