Municipal solid waste incineration (MSWI) technology has the advantages of energy recyclability, in-situ incineration, fast processing speed and high capacity reduction rate. However, its inputs have characteristics of diversity and time-varying due to differences in economic development, living habit and natural environment. In addition, it is also influenced by the operating difference, equipment maintenance and seasonal alternation. Thus, it is difficult to maintain MSWI process to run in optimized operating conditions. In order to ensure the safety and optimization of this process, this paper uses chemical process simulation software to simulate a MSWI process based on a grate furnace. First, the research object is described. Then, the simulation strategy and parameter settings of the whole incineration process are given. Then, the whole process is simulated and analyzed. The simulation results show that the O2 concentration in the G1 flue gas can reach up to 15%, which meets the requirement of full burnout of combustibles. In the flue gas G3, the error between the simulated value of the pollutant and the actual value is within an acceptable range. The simulation results can effectively reflect the status of MSWI. So, it provide effective support for constructing an incineration mechanism model of a near-real MSWI process.