The installation procedure of a Steel Catenary Riser (SCR) hanged in the internal section of the semi-submersible production platform is studied, and a scheme is given for tension transferring, lifting and lateral settling of SCR in semi-submersible platforms. The numerical method is adopted to simulate the above processes for verification. Two cases with empty and flood are considered and the SCR top tension, minimum interval between pull-in wire and pontoon, inclination angle at the top of the riser are given as results, which could be the basis for decision of the maximum tension requirement of the riser lifting system. The results are applied to the ultra-deep water oil and gas field project "No.1 in Shenhai" in China, in which the feasibility of the scheme based on this method is verified.