The invention provides an overhead transmission line project comparison and selection method based on the full life cycle. The method comprises the steps that 1, according to data of the use amount of each material and equipment used in the production and building process of transmission line schemes to be selected for constructing a power grid and energy resources consumed by producing materials and equipment of a unit of use amount, the basic energy consumption of each consumed material and equipment is calculated, and the total basic energy consumption of each transmission line to be selected is obtained; 2, the difference value of running energy consumption under the system initial framework structure and running energy consumption under the grid-connected operation condition of each transmission line to be selected is calculated; 3, the energy consumption return rate of each transmission line to be selected is calculated and is the specific value of the energy consumption return value to the total basic energy consumption, and the energy consumption return rates serve as the bases for selecting a transmission line project. The overhead transmission line project comparison and selection method based on the full life cycle not only can improve the comparison and selection efficiency of an overhead transmission line, but also can play an important role in energy conservation and emission reduction of the power grid.