Abstract: The conductor connection modes in 1000 kV substation are various, and its surface electric field distribution is extremely uneven due to proximity effect. Corona discharge is easy to occur on the conductor surface, especially in high altitude areas, thus the corona voltage of the conductor will be reduced. In order to prevent the corona on the conductor surface and optimize the electromagnetic environment of the substation, a reasonable conductor type must be selected. We propose a method of substation conductor selection based on numerical calculation and finite element simulation and supplemented by corona simulation test. The control value of conductor surface field strength is obtained, and the E_m/E_c, audible noise L₅₀, and electric field distribution of conductor are calculated when different selection schemes are adopted. Besides, the conductor selection scheme of UHV substation at 4000 m altitude is given and verified by the corona tests. The results show that the recommended control value of conductor surface electric field strength is 1.84 kV/mm. Meanwhile, if the UHV substation at an altitude of 4000 m still uses four-bundle conductors, E_m/E_c and L₅₀ will increase by 50.0% and 23.7%, respectively. When the selection scheme recommended in this paper is adopted, E_m/E_c and L₅₀ are 0.79 and 60.29 dB, respectively, the maximum field strength on the conductor surface is 1.67 kV/mm, and the corona extinction voltage of the conductor at high altitude is 770 kV, which meets the requirements of corona protection of the conductor at 4000 m high altitude UHV substation. The research methods and results in this paper can provide a basis for the subsequent selection of UHV substation conductors in high-altitude areas and the construction of green and environmental protection power grid projects in China.