The thermal expansion and contraction of the metal material is the fundamental causes of thermal error.The traditional thermal error compensation method is based on realtime temperature of machine,forecasts the appearance time and size of thecontrols the position of the tool to compensate.The traditional method has some defects such as being delayed.This paper imagines that we make negative thermal expansion materials as a tool,and unites out the negative deformation obtainedby finite element analysis with machine toolworkpiece position error by using simultaneous regression method to reduce processing errors.The results are expected to provide a new approach to thermal error expansion of machining parts.