In order to fix the problems of having crossing points and uneven branch line length distribution in the existing algorithm for the intelligent arrangement of the case with mixed cables and overhead lines, a method of center of gravity inspiration method combined with particle swarm optimization is proposed. Firstly, the method determines the preliminary arrangement of the transmission lines based on the multi-branch tree traversal. On this basis, the symmetry relationship of the branch line is optimized by the center of gravity inspiration method. Finally, the particle swarm optimization algorithm is used to optimize the key parameters of the center of gravity inspiration method to further reduce the number of crossing points and improve the uniformity of the branch line length. The multi-branch tree method, the common information model method, the substation configuration description file method and the proposed method are used for the intelligent arrangement of a 110 kV system with mixed cables and overhead lines, and the proposed method is validated.