The paper aims to design a household foldable seat that can meet the needs of users, so as to reduce the occupancy rate of seats in the indoor space of small apartments. The design of the existing foldable seat was analyzed in combination with TRIZ theory, and the relationship between users and products was determined through the analytic hierarchy process (AHP) method. One target layer, six primary indices and fifteen secondary indices of the functional demand index of the folding seat were derived, and then the weight values of each functional index were calculated, and a consistency test was carried out to determine the product design requirements that users need to solve urgently. And 40 invention principles of TRIZ theory were applied to solve this problem. The combination of AHP method and TRIZ theory can accurately analyze the user's preferences and specify the design focus for the design of household foldable seats, so as to design suitable seats.