In the B-to-B sector, the number of customers is relatively small, but a single customer relationship maintenance costs are very high. So discovering the actual value of every customer has great significance to enhance the firmpsilas customer relationship management and reduce the customer maintenance costs. Some traditional evaluation models such as customer life-time value (CLV) models can determine the economic value of customers well, but cannot reflect the customerpsilas actual value. A new customer-evaluation model based on the Topsis method was developed in this paper. Every customerpsilas real value can be determined from the comprehensive perspective based on a composite index system by using this model.