This paper aims to improve the clarity and effectiveness of interaction between users and products, thereby studying the design method of consumer product. Affordance is originated from ecological psychology. The design method for redesigning consumer product by combining Function-Task interaction Matrix and Principal Component Analysis. This method helps designers to identify affordance feature by analysing the interaction mode between users and products, which can provide a clear design basis for designers. Taking hair dryer as case study. Firstly, affordance factors are established by the Function-Task interaction Matrix; going forward, the hair dryer affordances and their correspondence weight are analysed by Principal Component Analysis in SPSS. From the result, these affordances can be divided into such three categories:functional affordance, operational affordance and information affordance. Finally, on the basis of the above and the needs of the user population, the scheme is correspondingly refined. In conclusion, this method not only clarifies affordance between users and products and its weight, but also enriches the practical research of affordance in the design.