Based on the method of time domain nonlinear coupling analysis, the platform motion response and mooring line tension response are calculated by changing the mooring parameters of the platform mooring system. Using the maximum offset of the platform and the mooring line tension safety factor as the preferred objects, the effect of the changes in mooring parameters on mooring performance is investigated. The results show that: the hydrodynamic coefficient of the mooring line section and the internal angle of the mooring line have no significant effect on the response of the mooring system of the platform; the mooring performance is very sensitive to the change of the number of mooring lines; increasing the number of mooring lines within a reasonable range causes the maximum tension of the mooring line to decrease rapidly, and the maximum displacement of the platform is also reduced; the mooring performance of the platform can be greatly improved by reasonably selecting the distribution of the mooring line material, the total length of the mooring line and the intergroup angle of the mooring lines.