Abstract: The spatial pose and shape of flexible cable harness are easy to change during the wiring in complex mechatronic products, thus lead to inaccuracy of the sampling information of cable harness in the process of wiring, and seriously affect the efficiency of wiring. This paper proposes a physical characteristics modeling and deformation simulation method for flexible cable harness based on exact Cosserat model. First, for the large deformation characteristics of cable harness, we build an activity frame and a parameterized model of cable harness, and analyze the spatial evolutionary process. Secondly, we describe the spatial pose and shape of cable harness, and establish a physical characteristics model of cable harness based on exact Cosserat model by comprehensive consideration of the cable harness geometry and physical properties, and then construct the dynamic equilibrium equations of flexible cable harness. Finally, to simulate the deformation process in the process of wiring, we solve the physical characteristics model by using the numerical integration solution method. In this paper, we design and develop a corresponding prototype system of flexible cable harness wiring/simulation, and verify the proposed method by a specific case.