Studying the propagation mechanism of cascading failures is of great significance for identifying the vulnerable lines in power grid and formulating prevention and blocking strategies for cascading failures. Based on analyzing the development progress of cascading failures

the concept of cascading failure pattern is defined. A cascading failure pattern mining algorithm(CFPMA)based on sequential pattern mining technology is proposed to analyze massive simulation data and identify critical cascading failure pattern of power system. Finally

taking the IEEE 39-bus system and a real provincial power system for example

CFPMA is used to mine the main cascading failure patterns

and the cascading failure propagation law is analyzed by combining the power grid topology and power flow. The test results show that the proposed method has a good effect on identifying the main cascading failure patterns and the vulnerable lines.