Abstract: The height of fractured water-conducting zone is the important parameter for determining waterproof coal pillar and evaluating the coal mining safety under the water，and has the important practical value for the safety in production of coal mine，water preserved mining and ecological protection.The empirical formula method，field measurement method，physical simulation and numerical simulation method of fractured water-conducting zone determination is summarized and compared.The practical conditions，advantages and disadvantages of various methods were summarized.The comprehensive observation and detection of two methods or more is recommended to verify each other.The field water leakage observation and borehole TV are used as the main methods，and the geophysical detection method as auxiliary means are determined the height of water-conducting zone.The physical simulation or numerical simulation method are also as the auxiliary to make the dynamic study on overburden strata failure law from the plane and three-dimensional perspective，forming the integrated exploration and analysis methodology from point to plane and to space.The research results provide an important basis and technical support for the coal pillar design and safety mining under water.

Key words: Fractured water-conducting zone, Empirical formula, Field measurement, Physical simulation, Numerical simulation