This paper proposes the design reuse model of complex product which is integrated with CBR (Case-Based Reasoning) and is established under virtual manufacturing environment. This model is aimed at the issue how to rapidly extract reuse design knowledge and select matching reuse design model to ensure that complex product can quickly respond to customers’ diverse and personalized demands with low costs during designing and manufacturing complex products. This model makes reasonable planning for the existing case design and considers the usability and economy during product design comprehensively. And on this basis, this paper researches the reuse design strategy ensuring the rapid response of complex product and the method of reuse process, develops the design system basing on case reuse technology and achieves the rapid design and analysis of product. Besides, the proposed design reuse approach is going to be tested by integrating with the farm dump truck produced by one certain machinery Co., Ltd.