The invention provides a power network stability simulation method. The method comprises the steps that the status information, node connection information and current load information of a power network are acquired; the respective reliability value is calculated by using a plurality of different methods; the weighting parameters of a plurality of different methods are acquired respectively; weighted summation is carried out on a plurality of different methods; whether the reliability simulation result exceeds a first threshold value range is judged according to comparison of the summation result with a first threshold value; if the first threshold value range is exceeded, a warning signal is adopted to start a first-level pre-plan; if the first threshold value range is not exceeded, whether any one exceeds a second threshold value; if any one exceeds a second threshold value range, a reminding signal is adopted to start a second-level pre-plan; if any one does not exceed the second threshold value range, the information in the above steps is stored in a repository; and the above steps are repeated to carry out iterative loop. The method can accurately, fast and timely detect problems. The corresponding efficiency and the utilization of effective information can be improved. Problems can be rapidly solved. A serious power failure can be avoided, or danger caused thereby can be reduced.