Abstract: Combined with optimal control theory, wheel rail creep theory and Kalman filtering method, a holographic model is established for the identification of wheel & rail contact forces. The identification results were compared with numerical simulation and inspection data. Firstly, the identification problem was converted into the design issues using an optimal control strategy, an optimal acceleration state tracker was developed by using the state space equation of a vehicle system. Secondly, the design issues were inversely solved using SVD technique, and the evolution history of contact forces were obtained. The predicted contact forces were positively updated using Kalman fliting method. Finally, the relation between contact forces and wheelset displacements were updated by using the wheel-rail creep theory, the ill-posedness problem was thusly solved, and independent left/right lateral forces can be obtained. The identification results were compared with the numerical simulation and the experimental finding, and it showed that the correlation coefficient of identification lateral/vertical forces and simulation forces were 0.69/0.8, and that the correlation coefficient of identification lateral/vertical forces and verification forces were 0.51/0.69.