Abstract: In order to study the effects of silica-alumina ratio and changes in water content on the adsorption performance of epoxy ethane, a combined strategy of grand canonical Monte Carlo (GCMC) and isothermal-isobaric ensemble (NPT) was used to analyze the adsorption of ethylene oxide (EO) on HZSM-5 zeolite under different humidity on molecular level. The results show that, under two different relative humidity (RH) conditions, which are 30% and 90% respectively, the HZSM-5 zeolite with 25~120 Si/Al ratios have better adsorption performance of ethylene oxide with concentration 1 000 mg/m³.The adsorption quantity of HZSM-5 under low humidity is slightly higher than that under high humidity. At last, the simulation results were validated by experiment. It means that the simulation conditions and methods used are suitable for the adsorption process analysis of EO on ZSM-5. The simulation results provide a theoretical basis for seeking out the EO adsorption materials and optimizing the remove conditions of EO.