Abstract: To explore the dynamic behavior of the evolution process of the roof instability in gobs, a fluid-structure coupled mechanical model was established for the instability of the whole roof cut-off in a mine, and the evolution of wind speed and wind pressure in instable gob was obtained using Matlab. By using FLUENT software, the longitudinal wind speed and the velocity distribution at the cross section of the roadway propagated by the shock air wave were obtained, so as to reveal the dynamic characteristics of the shock air wave disaster. The results show that with the increase of the falling height of the roof, the wind speed in the gob has experienced two stages of acceleration and deceleration. The wind pressure curve can be divided into a slow rising stage and an exponential rising stage. The impulse gas velocity along the roadway longitudinally follows the distance. The increase shows a decrease in negative exponential function, and the cross-sectional flow velocity distribution of the roadway is divided into the left high flow velocity area and the right low velocity flow area. The wind speed at the left bottom corner of the cross section of the roadway is the largest.