Abstract: The paper introduced the principle of the seam water injection and dust control.From the coal structure features, the seam water injection kinematics and the seam water injection wetting theory, the paper reviewed the present status of the seam water injection theory at home and abroad.The double porosity medium theo ry and model was applied to describe the coal cracking and porosity and stated the water movement process in coal.Meanwhile, the paper introduced the judgment met hod and index of the coal quality wetting degree.The paper stated the grades of the seam water injection technique.The paper introduced the achieved research and de velopment, the patent achievements and products markets on the study on the seam water injection equipment and technology and in detail summarized the present sta tus and the products markets on the study of seam water injection wetting agent at home and abroad.Finally the paper provided the existed problems in the study on th e seam water injection theory and technology and the future development orientation.