To solve the problem of limitation of assuming constant market demand scale and not applying to multi-brand enterprises in most measurement models of customer equity(CE),this paper applied markov matrix to simulate the competition between enterprises and the brand switching of customers,and analyzed the influence of mutative demand market scale on CE with the method of trend forecasting,based on full consideration of cross-purchases and propaganda of public praise,which had significant impact on CE measurement but were ignored in most models.Eventually a four-dimensional driven measurement model of CE under the condition of mutative demand market scale was established.In the application study of the model,forecast method,linear regression method,principal component analytical method and logistic regression analysis were used to measure samples’ CE.The results showed that the change of customer quantity had caused remarkable change of CE,and the mutative demand market scale was a key factor to be reckoned with.This model can make more accurate measurement of the CE and is operable,so that it can guide practice more effectively.