The invention belongs to the technical field of mine construction and relates to a method for online monitoring of a tailings pond safe state. The method for the online monitoring of the tailings pond safe state is based on the fast search algorithm and a tailings pond online monitoring system is used for achieving the online monitoring. The online monitoring system comprises a monitoring device, a data information collecting unit, a data information analyzing and judging unit and a result processing unit. The monitoring device comprises a static force level instrument, a sliding gradiograph, an osmometer, a water level indicator, a water quality monitoring instrument, a rain gauge, a video camera and a material level instrument. The data information collecting unit is respectively communicated with each unit device through electric information, data information of various kinds is collected, concentrated analysis and processing are conducted on the data information through the rapid search algorithm according to the collected information data and the current condition of a tailings pond, so that the tailings pond safety state is judged and displayed; the method for the online monitoring of the tailings pond safe state is simple in technology step, flexible in operation, reliable in principle, low in maintaining cost, strong in expansion performance, widely suitable for requirements for different monitoring indexes and environment-friendly.