Abstract: This paper develops a method for measuring the mechanical parameters of nuclear graphite based on digital image correlation (DIC) method, and gives detailed data processing method and measurement procedure. The experimental results show that the Young's modulus and Poisson's ratio extracted from DIC data are in good agreement with those from the strain-gauge-based method, which verifies the feasibility and accuracy of the DIC method. In addition, the complete stress-strain relationship was obtained from DIC method, confirming the superiority of DIC method in measuring the mechanical parameters of materials with large deformation. Furthermore, the DIC method is easy to operate and efficient in identify the loading misalignment, making it convenient in large number of tests and reliable for the data acquisition for brittle materials testing.