In recent years, water disaster in coal mines has always affected the normal production of coal mines. Mine water prevention and mine hydrogeology has become an urgent issue to be solved in coal mines. This paper mainly introduces the DC electrical method for mine water prevention and guidance. Through the arrangement of all the ground electrodes, it collects the resistivity. Then, in the 2D resistivity inversion software, it obtains the 2D resistivity section, which reflects the situation of underground water occurrence more intuitively. Through practical work, water flowing fractured zone and water range in goaf have been delineated, which provides accurate information for mine water prevention.