The invention discloses a designing method for a three-butterfly-shaped multi-loop power transmission line pole tower. In an existing multi-loop power transmission line pole tower, a more obvious contradiction exists between the rationality of the structural stress and the width of a line corridor. According to the technical scheme, the designing method comprises the steps that firstly, the control range of an electrical clearance circle on the condition that wires are arranged in a triangular mode is determined according to the objective requirement of overhead power transmission line design specifications to the horizontal wire spacing distance of the wires, and the tower head size of the three-butterfly-shaped four-loop pole tower is determined by taking the control range as a boundary condition; secondly, the full-stress iteration and optimization process is performed on three types of the pole towers including the three-butterfly-shaped four-loop pole tower on the basis of Daoheng pole tower rapid modeling and full-stress calculation programs; lastly, all-dimensional comprehensive index comparison is performed on the aspects such as steel quantity indexes for a single-based pole tower, the width changes of the line corridor and the basic acting force. According to the designing method, the core contradiction between the stress rationality of the pole tower and the width of the line corridor is effectively solved.