The transmission line is a necessary way for the power generation system to transmit electric energy, and it is also a necessary condition for the configuration of the power grid. With the advancement of modern power system construction and the continuous growth of power demand, the requirements for the reliability of transmission lines are getting higher and higher, and its safe operation is related to the reliability of the power system. The purpose of this paper is to study the 3D design of overhead transmission lines based on oblique photogrammetry technology. A set of 3D construction methods based on oblique photogrammetry oblique photogrammetry technology is proposed. According to the existing experience and achievements, the method of each key link is compared, and a feasible and efficient method for constructing an overhead transmission line model based on oblique photogrammetry image sequence is summarized. The automation of key steps in the model building method is achieved through an oblique photogrammetric modeling software system. Based on the construction method of power tower nesting modeling and wire fitting modeling proposed in this paper, the three-dimensional model of overhead transmission line is designed through the example of power tower and wire modeling design, and its accuracy is verified.