The invention discloses a power transmission path optimal selection method based on path traversing and sensitivity combining. An input module, a breadth-first search module, a sensitivity analysis module and a power transmission path optimal selection module which are arranged in a power grid control system are provided. The method provided by the invention mainly comprises the steps of: utilizing a breadth-first search algorithm to search for all direct-purchasing electricity power transmission paths, then utilizing a sensitivity analysis method to calculate the current sensitivity of each direct-purchasing electricity node to each power branch in the power transmission paths, carrying out accumulated calculation to obtain an accumulated sensitivity of each power transmission path, carrying out optimal selection ordering on the direct-purchasing electricity power transmission paths according to the sequence from large to small accumulated sensitivity values, and optimally selecting the power transmission path which is more influenced. According to the invention, a power scheduling center is enabled to arrange power generation and utilization plans, and heavy currents or overcurrents of power branches are prevented.