The research of Service science, engineering and management （SSME） is depended on knowledge resources, and related to the process of serving. The research objective of this paper is oriented on a complex product design service which with the characteristics of disciplinary fusion, integration and coordination of knowledge, and the hypothesis oriented on knowledge flow was proposed for research this special service object. The content of this hypothesis is an experiential view, that is, modern complex product design process is driven by design task, and it is a knowledge flow process, whose core is new knowledge acquisition. Based on this experiential view, this study proposed a design process control and knowledge service research frame of complex product. Moreover, to promote the understanding and realization of the hypethesis mentioned above, the modeling and control of the design process of modern complex product through the process of knowledge flow, original knowledge acquisition of disciplinary subjects supporting for the construction of knowledge resources, and the construction and formal organization of resource unit based on knowledge base were conducted in this study. The knowledge flow-oriented hypothesis, experiential view and relevant prospective research results, are supposed to provide knowledge base and theory reference for the formation of SSME relevant axiom and theorem
