Abstract: In this paper, the global kinetic rate equations of the main and side reactions of ethylene oxide synthesis are studied in a gradientless reactor under industrial operating conditions. The two-dimensional heterogeneous model of fixed-bed reactor is set up for the simulation of industrial reactor. The Crank-Nicholson predicrot-corrector method is used in the integration for the gas phase and the iteration method is used for the solid phase.The accuracy of reactor model,global kinetic equations and heat transfer parameters were tested by comparing the calculated values with industrial actual values.These also show that the other transfer parameters cited in the calculation are suitable.The activity correction factors of the main and side reactions are correlated with time by regression of industrial operation data.The main and side reaction deactivation rates of sliver catalyst of ethylene oxide synthesis are also obtained through further research.The deactivation rates are used to forecasting the suitable time when the catalyst should be replaced and to optimize operating conditions in the later period of catalyst activity.