The work aims to propose a new design methodology, Motivation Design Theory, which can be used to address the problem of Requirements Beyond User Expectation (RBUE) in user-centered design. In order to obtain the RBUE, the motivation design theory was proposed based on previous researches such as motivation psychology, theory of planned behavior, and mirror theory. Through the design logic of the motivation design theory "moving from the end of requirement satisfaction to the beginning of motivation, the inner-loop mechanism of the motivation design theory and its methodological process were constructed. The inner-loop mechanism of motivation design theory, especially the incentive factors in the inner-loop mechanism, could be used to obtain RBUE, as demonstrated by the case of jewelry exhibition. The theory and methodology proposed can provide more accurate guidance for design than previous design methods, especially in the area of motivation design, which has an inherent advantage.