It plays an important role to identify and preferentially reinforce critical line in power systems in the secure and stable operation of power systems under typhoon conditions. In order to identify the critical line effectively

the location of transmission lines in the network topology structure

the operation state of power systems

the economic loss of the lines fault

and the influence of the lines parameter and external environment on the identification results are considered. Five multi-dimensional evaluation indexes

i. e. weighted line betweenness

improved power flow entropy

local variation

economic loss and the failure rate of lines

are presented to evaluate the importance of lines. The multi-dimensional evaluation indexes can comprehensively take critical characteristic parameters of complex power systems into consideration

which could overcome the limitation of single dimension of evaluation index. The optimal combination weight method

which aims at minimizing the sum of squared deviations between integration weights and the subjective and objective weights

is adopted to determine the weights of indices for considering both the subjectivity of the decision makers and the objectivity of the inherent relationship of the indexes data. The radar chart method is adopted to evaluate the transmission lines synthetically and identify critical line. The simulation results show that the proposed method can consider various factors in the identification of critical line comprehensively and better reflect the importance degree of the lines under typhoon conditions in the power systems.