As a critical component for power transmission in aerospace, construction machinery and related fields, the thermal protection performance of hydraulic pipelines directly affects system reliability and safety. Focusing on hydraulic pipeline thermal protection technology under high-temperature working conditions, this study conducts computational research on thermal protection design and completes temperature simulation verification. Firstly, the energy transfer mechanism of hydraulic pipelines under high-temperature conditions is analyzed. By integrating pipeline specification parameters, oil thermodynamic properties, and thermal insulation material performance data, a computational formula for thermal protection layer thickness is derived based on steady-state heat conduction theory. Subsequently, a three-dimensional thermodynamic model of hydraulic pipelines is established using the ANSYS platform for temperature simulation validation. The simulation results confirm the accuracy of the derived thermal protection layer thickness formula while revealing the temperature rise patterns in hydraulic pipelines. This research provides technical foundations for thermal protection design of hydraulic system pipelines operating in high-temperature environments.