The work aims to clarify the corresponding relationship between the functional elements and need elements of electric water heater products, and to improve the user satisfaction of electric water heaters.By constructing an integrated design model of QFD and TRIZ, the affinity graph was used to screen and analyze customer needs, QFD was used to sort out the weight of customer needs and construct a house of quality, to clarify the key design elements; the types of contradictions in the house of quality were judged by TRIZ analysis. Then, the design requirements were converted into contradictions with engineering elements, and a method to solve the contradiction was proposed with the corresponding invention principles in the Altshuller matrix. The optimal design scheme was screened by the fuzzy comprehensive evaluation method, and the final evaluation result showed that the new design scheme satisfied the target problem optimization of the actual market user needs. The change from user's passive discovery of product parts life exhaustion to an active prompt of product information with structure assisting user operation improves the matching degree between user needs and product functions, shows the importance of the integrated design method of quality function deployment theory and inventive problem solving theory for the conceptual design stage of products, and provides a reference for the subsequent research on the design of indoor smart home appliances.