The article analyzes the adaptability of SMC model, based on the features of purchase decision in B2B market. At the beginning of this article, we introduce the SMC model and its hypothesis, and then modify the model considering the characteristics of B2B market and the effects on purchasing decisions from the services provided by suppliers. Finally, we examine the modified model by a case, and compare the forecast results of the unmodified model with those of the modified model. The result proves that the modified model is more accurate and more scientific than the general SMC model on predicting the customer equity purchasing value in B2B market. Additionally, it also testifies the comprehensive adaptability of SMC model which must consider the adjustment of parameter calculation on the basis of the characters of purchasing behaviors.