Abstract: For problem that existing method of seepage line monitoring cannot fully reflect situation of tailings dam because of few monitoring points, the paper proposed a design scheme of seepage line monitoring system for tailings dam based on high density resistivity method. The system collects data from monitoring points through intelligent electrode switch. It gets resistivity distribution of the tailings dam profile based on analysis and calculation of the collected results, and know position of seepage line of the tailings dam and abnormal geological condition of the tailings dam body according to resistivity iso-surface figure. It provides scientific basis for risk assessment of tailings dam.