Abstract: High-precision plane grating scale measurement system (PSMS) is the core measurement system of immersion scanner.Its measurement accuracy directly affects the positioning accuracy and settling time of wafer stage in immersion scanner.The plane grating scale (PS) is mounted on the plane grating scale carrier (PSC).Due to the low natural frequency of PSC,it is easy to be vibrated by the residual vibration of the main plate and the pressure disturbance of the high-speed wafer stage,so it is of great significance to study the vibration damping technology of PSC.In this paper,a new type of PSC vibration damping method was introduced,focusing on thermal decoupling technology and viscous damping vibration absorption technology.With the use of theoretical modeling,simulation analysis and test evaluation,the results show that the parallel system of viscous damper and flexible structure can significantly improve the dynamic characteristics of PSC structure,improve the measurement accuracy of plane grating scale measurement system and shorten the settling time of wafer stage.