This paper proposed a multi-objective power grid planning method considering multi-section transmission capacity and economics. Firstly, a multi-objective power grid planning model that considers the multi-section transmission capacity and economics is established. Then, normalized normal constraint method is employed to solve the multi-objective model and obtain a series of Pareto front solutions. Thirdly, the balanced Pareto front solution is selected based on the technique for order preference by similarity to ideal solution. Finally, the proposed method is compared with the single-objective power grid planning method on the IEEE 14-bus system. The experimental results show that the proposed method reduces expansion costs by 88.9% while ensuring a significant improvement in transmission capacity.