Digital image correlation (DIC) method is an indirect method for measuring displacement and strain. It has been widely used in related fields owing to its advantages of simple optical path and good adaptability. In this study, first, typical hollow disk metal parts are taken as the research objects and a self-built thermal deformation device is used to heat and control the temperature of the parts. Then, the DIC method is used to extract the image features of the parts before and after temperature change to calculate the thermal deformation of the outer diameter of the parts. Finally, ANSYS simulation software is used to simulate the thermal deformation of the parts under the same temperature change. Experimental results show that the thermal deformations of the parts measured using the DIC method correspond well with the ANSYS simulation results, which indicates that DIC method can be used to measure the thermal deformation of metal parts.