This paper introduces a visual calibrator for configuration file of intelligent substation reconstruction and expansion based on Linux system, which can realize the comparison of SCD file and configuration file of bus protection process layer before and after intelligent substation reconstruction and expansion, and prevent the occurrence of wrong modification of bus protection configuration file. Firstly, this paper introduces the overall architecture of the calibrator, including the visual calibration module of reconstructed and expanded equipment and the interval calibration module of process layer configuration file; Then it focuses on the function and mechanism of the core cyclic redundancy check module of the calibrator. The Visual verification module and configuration file interval verification module realize the comparison of SCD files and bus protection configuration files by calling the core cyclic redundancy verification module; Finally, the function and application effect of the calibrator are demonstrated by applying it in the reconstruction and expansion of a substation. The visual calibrator for the configuration file of intelligent substation reconstruction and expansion lays a foundation for the realization of intelligent operation inspection of intelligent substation.