With the aircraft hydraulic system developing toward high pressure and high power, the problem of heat and temperature increasing in the hydraulic system has received widespread attention. Axial piston pump, one of the most important energy conversion devices in hydraulic system, has a great contribution to the power loss and temperature increasing. Therefore, a good thermal analysis method for the axial piston pump has an important significance for the thermal design and temperature control of the hydraulic system. Traditional thermal analysis methods for axial piston pump, such as the average oil temperature method, the software simulation method and the thermal network node method, are unable to meet the related requirements of modern aircraft hydraulic system thermal analysis and thermal design, because they are unable to provide accurate, efficient and concise analysis result. In this paper, aiming at the related problems of axial piston pump heating in aircraft hydraulic system, the thermal network model of axial piston pump is established based on the lumped parameter thermal network, and the thermal analysis simulation under different working conditions is conducted, which validates the accuracy and effectiveness of the model and provides a reference for the thermal analysis of axial piston pump and hydraulic system.