The heat of the positioning platform is mainly caused by conduction of each functional unit, when it affected by the influence of internal and external heat source at work, the temperature of units would change, and the condition would make the platform component stiffness change, then lead to positioning platform dynamic characteristics change. In this paper, the finite method analysis platform dynamic connection stiffness with the regularity of temperature change, and by using the grey correlation method to optimize the platform stiffness influence of the four largest temperature sampling point, through the neural network modeling method to establish high precision positioning platform stiffness model, provide theory for the research on platform of dynamic characteristics of the model.