The purpose of after-sales service is not only to meet the service needs of users after purchasing products, but also to collect customers' opinions and suggestions, understand the dynamics of customers' needs, and use it as an effective means to improve product quality and promote re sales. Lianjun machinery has always been adhering to the principle that "service is the only product of Lianjun machinery", is "the foundation of enterprise survival", and is "the core driving force of enterprise development"