Abstract: In order to improve the forecast accuracy and adaptability for rotating machinery working conditions with unsteady and nonlinear features,an optimization prediction method of variable weight RBF combination model was suggested.This model was built based on variable weight RBF network.The samples were weighted according to the time to output and the combined models were selected according to the average relative error while the model built.As a result,the sufficient effective information was used,and the fact that new and old information taking different effect on the future state was stressed.The method was verified by measured data.The accuracy of variable weight RBF combination forecasting method was better than single RBF model and single weight combination forecasting methods.This method is simple to program and more adaptable on prediction with high farecast accuracy.