Customer is a fundamental factor to the survival of business. In order to effectively pull the customer resources and realize the alternating of the old and new customers, companies tend to spend a lot of manpower, material and financial resources. As to effectively accelerate and improve the development of companies' businesses, CRM system is to be very important. Therefore, this paper proposed a kind of CRM system structure based data mining technology research. Through, the CRM system structure and the theory of data mining, this paper conducted instance analysis and experiment to the application and implementation steps of the CRM system in the data.