Abstract Most existing studies simplify conductors as isothermal cylinders, neglecting their actual structure and the inter-conductor contacts. This is especially problematic in regions like Northeast and Northwest China, where the conductors face harsh working environments due to significant seasonal temperature variations. Additionally, there is a lack of research under extreme low-temperature conditions. Considering these factors, a temperature field in low-temperature environments was established based on the heat conduction equation. A finite element model and a mathematical model for the transmission conductor were developed using the actual structure of the JL/G1A-240/30 type steel-core aluminum stranded conductor as a reference. Constraint conditions were set, and the model was simulated under various environmental conditions using the finite element ANSYS software. This simulation calculated the radial temperature distribution of the conductors in low-temperature environments, along with the combined effects of transmission line current load, air convection cooling, sunlight intensity, and wind speed on the radial temperature distribution. The results indicate that this method can effectively determine the radial temperature values of transmission conductors under different meteorological conditions, which are significantly influenced by environmental temperature and wind speed. This is beneficial for enhancing the operational safety and stability of transmission lines, achieving dynamic capacity expansion, and improving the transmission capacity of the lines.