Abstract: In order to research the impact of baffle location on the shockwave propagation characteristics in a fork road of closed roadway, using ANSYS to simulate the two-dimensional explosion flow field, then comparing the baffle in the different situations and positions, we monitor and draw the overpressure change curves of each point in tunnel and the velocity vector diagrams at baffle, which can be used to analyze the propagation law of explosion shock wave. The result shows that when the single baffle is placed on the direction of shock wave, the influence on overpressure at the bottom of tunnel has little change compared with the same tunnel without baffle, but having the best effect on reducing overpressure at the center of closed tunnel, on the other hand it has a certain stability effect on pressure fluctuation. When double baffles are set on the direction of shock wave, the overpressure has the greatest reduction in the center of closed tunnel. On the contrary, when the double baffles are placed on the opposite side and the inlet baffle at the entrance is on the side of shock wave, the overpressure weakening effect on the inner surface of the roadway is the best.