In order to mitigate the influence on the power supply reliability for the unevenness of the distribution of power supply and load and improve the availability of power equipment，a method of multi-objective transmission expansion planning（TEP）considering the unevenness of power flow distribution of tie-line groups is proposed.The unevenness of load and power distribution is considered from a regional perspective.Based on the division of interval lines，the coefficient of variance for the load factor of tie-line groups is used as the index of the power flow distribution unevenness of tie-line groups，which reflects the power exchange between different zones.Considering both expansion cost and loss of system operation，a multi-objective optimization model for TEP is developed.By using the genetic merit factor and structure sensitivity sequencing in the solving process，the compromise solution of multi-objective optimization is realized through improved genetic algorithm.An example of power network planning for a region in East China has proved the method proposed effective and feasible.