The invention relates to an analysis, early warning and control method for power grid security. The method uses a security analysis and early warning system of the power system, the security analysis and early warning system has a distributed coordination frame structure and comprises a platform and an application system; the method comprises the following steps: the power system operates at a low load condition; the load climbs; a heavy load mode is carried out; the system has small disturbance; an N-1 fault occurs in the heavy load mode; a heavy load overhaul mode is carried out; an N-2 fault occurs in the heavy load mode; multiple breaking faults occur in the heavy load mode; the system enters a recovery mode after sectionalizing; and the power system is stable. According to the systematical summarization and analysis on the power grid security, the invention provides a comprehensive power grid security method covering all kinds of security analysis systems and control techniques and provides a representative model for describing all kinds of dynamic processes of the power grid, thus providing the foundation for the coordination and application of all security analysis systems and being beneficial to solving all kinds of problems in the states of large power grid alert and emergency.