This paper aims to reduce the input and output of clothing brand and improve the competitiveness of clothing brand for meeting the current trend of clothing brand and IP brand. Based on the perspective of fashion brand product innovation driven by star IP, we put forward hypotheses on product innovation mode from three aspects of core design, product semantic design, and product extension design, construct a research model of "behavior perception purchase intention", and then empirically test the hypothesis by designing consumer questionnaire. After survey, product core design significantly affects consumers' purchase intention of clothing through product perception and brand perception. Product semantic design variables have no significant effect on purchase intention, while product extension design has a positive effect on purchase intention. It shows that star IP core products, star IP semantic products, and star IP extension products promote consumers' purchase intention of clothing brands.