To explore the actual needs of users of oral irrigator,to obtain their key needs and the functional requirements associated with them,and to design oral irrigator products that better meet the actual needs of users.Firstly,we obtain users'needs through user observation and user interviews,then we quantify the weights of the needs by using the AHP model,and then we use the QFD relationship matrix to obtain the key functional requirements that meet the users'needs.The innovative design is carried out for the key demand elements and key functional requirements,and evaluated by fuzzy evaluation method.The AHP-QFD method can effectively explore the actual user needs and transform them into specific functional requirements,which is of reference significance for related product design research.