The prerequisite of realization of adaptive control of computer numercial control (CNC) machine tools are having relevant dynamics model. The key of implementation of adaptive control of vertical displacement of heavy precision CNC machine tools is the establishment of film thickness dynamics model with nonlinear factors of load, temperature, and etc. Aimed at no adaptive control model suitable for hydrostatic guideway film thickness, based on the NavierStokes equations, nonlinear dynamics model and simplified model of hydrostatic guideway film thickness were proposed, and both of them could be used for adaptive control. The model had the characteristics to reflect the relationship between guideway load change and film thickness variations, and included the speed and acceleration term of film thickness change, which is suitable for precision hydrostatic CNC equipment. After the simulation by using Simulink tools, model calculation accuracy magnitude reaches 10-4, which results verify the accuracy of nonlinear model and approximate model. 