Abstract: Mining area of Handan and Xingtai is one of the typical coalfields with a high risk of water leakage in north- east China. The technology used to prevent the water leakage in the shafts with large depth and high water pressure is to pre-dispose the water leakage in the Ordovician limestone from ground surface,namely the multiple branches hori- zontal directional drilling and grouting technology. Though the seriflux diffusion mechanism was studied comprehen- sively,the models proposed were based on the horizontal fissure with vertical injection hole. However,in the multiple branches horizontal directional drilling and grouting technology,the horizontal injection hole was applied to fill the fis- sure in the Ordovician limestone. Therefore,the seriflux diffusion mechanism in the fissure of aquifer proposed herein was based on horizontal injection hole. Firstly,the whole injection process was divided into three stages,which were described by individual equations,respectively. Secondly,the change of flow front of seriflux in the vertical fissure was analyzed. Thirdly,the fluid dynamic model was built to describe the relationship between the injection distance and injection time. Fourthly,the change of flow front shape of seriflux and the choice of injection parameters were discussed by a numerical simulation method based on the Hele-Shaw model. The results obtained in the present study are useful to design the injection holes and injection parameters. The application of the multiple branches horizontal directional drilling and grouting technology has showed a significant beneficial effect.