In order to thoroughly investigate the potential user demands during the use of smart trash cans and enhance the user emotional experience, the work aims to design a smart trash can that is more user-centric. Guided by INPD method, an innovative product design method based on the concept of "Without Thought" and INPD-ANP-TRIZ was developed. Firstly, the concept of "Without Thought rize their behaviors, and explore underlying potential demands. Secondly, an ANP model was constructed to calculate and prioritize user demands. Thirdly, TRIZ theory tools were employed to resolve conflicts in user demands and derive a design solution for the smart trash can. Finally, the design solution was three-dimensionally modeled and its feasibility was verified by fuzzy evaluation methods. Through this method, a smart trash can was designed and validated to better meet user demands and emotional experiences after scheme verification. The product design method based on the concept of "Without Thought" and the INPD-ANP-TRIZ effectively resolves design conflicts while meeting user demands and enhancing user experience, thus achieving optimal smart trash can design, and provides ideas and methods for innovative design of related products at the same time.