Abstract：Traditionally, the static security analysis system of the regional power grid needs to process a large count of (expected) accidents. The on-line fault analysis system is established, which provides lists of (suspected) fault devices and related circuit breakers, reducing the calculation pressure of static security analysis, accelerating the calculation speed. Besides, the static security analysis system of the regional power grid usually displays final results as a table. The risk assessment system is developed, giving a mark for power grid security. The practice indicates that the improved system can reduce the calculation scope and times, reduce the pressure of computer calculation and improve the practicability of the static security analysis system.