Abstract: In this paper, a static simulation device was used to investigate the generation of gas and the change of sewage quality for catering sewage. And the relationship between the amount of gas production and change of sewage qualities were analyzed. The coefficients of several harmful gases were calculated. Results showed that the generated amounts of methane, carbon dioxide, hydrogen sulfide were increased with hydraulic retention time. The removal of CODcr was the major indicator of methane and carbon dioxide generation, while the removal of SO42- was the major indicator of hydrogen sulfide generation. Methane, carbon dioxide and hydrogen sulfide generation coefficients were 3.71～17.9g/kg as the removal of CODcr, 24.5～40.4g/kg as the removal of CODcr, 1.50～7.10g/kg as the removal of SO42-.