Abstract: We use FLUENT software to simulate the two-dimensional model of exhaust flame arrester, and analyze the influence of the thickness of flame fence and the gap of the fence on the quenching distance and the pressure loss. By regression analysis, we obtain the regression model of the optimization objective, also obtain the multiple objective function by using the linear weighted method combined with the regression model of quenching distance and pressure loss, and carry out the optimal solution of multi-objective function under the condition of certain constraints. The results show that the quenching distance becomes small and the pressure loss becomes large when fire retardant layer thickness becomes larger and fence gap becomes smaller; the flame quenching distance and pressure loss of fence type arrester is the smallest when fire retardant layer thickness is 50 mm and fence gap is 0.25 mm.