Abstract：The previous water injection into coal seam was applied when the tunnel was excavated in order to solve the rockburst problem in Muchengjian coal mine. The single drilling hole isobaric water injection was put into effect on site in 6178 excavation working face of this coal mine and the water increment around the drilling hole was measured. Then the model parameter was inversed by using variable-tolerance-band optimization search method and the water transmission and storage characteristic parameters were obtained，which showed that this coal seam has bad water transmissibility and belongs to low-wetted saturation，so the high-pressure water injection is suitable for the coal mine. The dynamic changing processes of water injection under 7.0 MPa are described by visual numerical simulation in detail. The dynamic variable relation among pressure-time-wetted perimeter of water injection was formulated by numerical simulation trial in the end.
