The electro-hydrostatic actuator (EHA) is replacing the traditional hydraulic actuator to become an important part of the aircraft hydraulic system, because of its power by wire, easy maintenance and high reliability. But the application of EHA is limited by its disadvantage of heat dissipation. Therefore, it is necessary to establish the thermodynamic modeling and analysis of the thermal performance of EHA. In this paper, the EHA one-dimensional multi-discipline models are established by Modelica. A flexible model library of each component of EHA with thermodynamic characteristics is carried out. An EHA model based on this components are established and simulated to evaluate the correction of the model. The simulation results indicates that the models can be used to simulate the dynamic of electrical, mechanic and thermal in high accuracy. It lays a foundation for the heat control of EHA.