The invention discloses a recognition method for vulnerable lines of a power system. The recognition method comprises the steps that 1, running state parameters of a current power system are collected, and the real power flow P of one line in the power system is determined; 2, an N-1 safety verification result is determined according to the real power flow P of the line, so that an influence degree matrix S of a correlation network of the current power system is solved; 3, an extensive matrix S is obtained according to the influence degree matrix S; 4, a PageRank convergency value of the corresponding line is calculated according to the extensive matrix S to determine the vulnerable degree of the line. According to the recognition method for the vulnerable lines of the power system, by collecting the running state parameters of the current power system and constructing the correlation network and the extensive matrix, the PageRank convergency values of all the lines are accurately calculated to determine the vulnerable degrees of all the lines, therefore, large-sample cascading failure simulation is prevented from being performed, and the recognition efficiency is improved on the premise that the recognition accuracy is guaranteed.