Objective Research on variable substitution to non-linear regression forecast model precision's influence, and seek the modelling method that can improve the forecast precision. Methods Based on the data mining,the transform in space and the weighted processing combined method, make full use of information that the primary data provide. Results Given modelling method of combination forecast model based on the data mining. Conclusion Based on data mining's combination forecast model's modelling method can reduce the serious influence that the variable substitution brings and has fully used useful information in the primary data. It obviously improved the accuracy of the prediction model.