As the development of large-scale Ultra-High-Voltage Transmission Construction, conductors with large section had been applied to various transmission lines, which actually had obvious advantages in both current carrying capacity and reliability of structure. Exactly and reasonably presenting the static configuration and sag of lines became one of most important questions in designing of lines and anti-vibration works. In this paper, characteristics of bending stiffness of conductors with large section had been carefully considered. The equation with constant torsion curvature of super thin elastic rod model had been used, and based on that, the curvature distribution function of single conductor within the span had been calculated through the harmonic balance method. Combing with numerical integration solution of Frenet-Serret vector equations, the conductor’s static configuration was obtained. By comparison with the catenary formula and the test results, presented method was verified to be available.