The simulation model of the methanation reactor can guide the optimization of the methanation process, which is of important research significance. However, the construction of the methanation reactor simulation model involves two parts: reactor modeling and reaction kinetics modeling, and the two models are coupled with each other. Neglecting the reactor transferring role and considering the kinetic model alone or solving the reactor model from the chemical equilibrium point of view without focusing on the kinetics will lead to low simulation accuracy, which makes it difficult to guide the optimization of the process effectively. The multi-objective optimization algorithm is used to identify the kinetic parameters of the methanation reactor model built in Aspen Plus, which can achieve high-precision identification of the parameters of the kinetic equation set with fewer data points, and the method can effectively solve the problem of identifying the parameters of the kinetic equation set in the complex reaction process by considering the reactor action and reaction kinetics at the same time. The results show that the multi-objective parameter identification method of the methanation reactor process simulation model can reduce the root-mean-square errors of CO conversion and CH4 selectivity simulation results to 1.96% and 4.59%, respectively, which are lower than those of the existing kinetic models.