In the scheme comparison and optimization design of power transmission line, it is necessary to use the tower charges (weights) in different schemes. The conventional estimation method of tower weight is to calculate one kind of height based on tower weight existed in an actual construction design. While the towers’ weight at other heights and under other loads are estimated approximately with formulas, which makes bigger error and trouble work, so a simple, practical estimation model of tower weight is required. Taking the type and weight of tower in "±800 kV tower typical design" as the data samples, amathematical mode based on nonlinear multiple regression analysis was established, the sample data were calculated and analyzed with simulation software Matlab, thus the mathematical relationship between tower weight and tower height, loading condition were obtained. Compared with the data of typical design and actual Hazheng construction design, the error of tower weight estimated by the estimation mode is small, while its accuracy is high, which indicates that the estimation mode is practical, effective, and suitable for the scheme comparison and optimization design.