Abstract: Aiming at the coordination problems of under-well project management,the interface management theory was applied to the special coal mine under-well project management,and a set of interface management theory system and practice methods of coal mine under-well project were systematically put forward.On the basis of the construction of system framework of coal mine under-well project,the coal mine engineering interface was divided into the three types(target interface,process interface and organization interface),and according to the given interface analysis process,the three kinds of interface were identified and managed respectively,which can realize the effective control of interfaces,effective coordination of relations between elements,and change under-well project into ground project.The engineering interface management practice of Kailuan Group shows significant effect of interface management improving production efficiency.