Abstract: Due to the limited experimental conditions, the establishment of the simulation model for the marine riser with super slenderness ratio is faced with many difficulties. In this paper, the latest hybrid experiment method for the mooring system of deepwater platform was introduced. Then, the characteristic parameters of truncated model were optimized by Matlab and Mathematic, e.g. elastic modulus, axial stiffness and mass per unit length, and a reasonable truncated model for steel catenary riser was established. Finally, the mechanical behavior of full water depth model was compared with that of truncated model by means of finite element simulation. It is indicated that the mechanical behavior of truncated model is similar to that of full water depth model and the calculation result of truncated model is accurate. Combined with the normal similarity principle, the small-scale physical model suitable for lab research can be established. The research results provide the theoretical support for the simulation experiment in the limited experimental conditions.