To obtain a hydraulic damper thermodynamic model that is much more realistic than the thermodynamic model of literature, research is carried out by introducing the stochastic uncertainty theory. The geometric variables of the hydraulic damper are defined as uncertain variables. The stochastic variables are defined with the stochastic factor method, and the stochastic thermodynamic model is established with the algebraic synthesis method. The results of the experiment are considered as the standards for verifying the correctness and superiority of the stochastic thermodynamic model. The results of the stochastic thermodynamic model and the thermodynamic model of literature are compared with the experimental results, respectively. The oil temperature at the stable state of the stochastic thermodynamic model is close to that of the experiment, indicating that the stochastic thermodynamic model is correct. The oil temperature curve of the stochastic thermodynamic model is much closer to that of the experiment than that of the thermodynamic model of the literature, indicating that the stochastic thermodynamic model is superior to the thermodynamic model of literature.