The invention discloses a CRTSIII-type track plate processing deviation automatic detection method. The method includes following steps: S1, pouring a cement detection pedestal, and putting a CRTSIII-type track plate to be detected; pouring a cement abutment, and mounting a Kuka robot; S2, utilizing the Kuka robot and a three-dimensional imager to form a data acquiring subsystem, acquiring high-quality point cloud data of the surface of each track bearing platform of the CRTSIII-type trace plate, an area between left and right side faces when the track plate is flatly arranged on the ground and part of the undersurface; S3, on the basis of a Polyworks2017 software platform, using C# language for secondary development, establishing a data processing subsystem, importing a design model and the point cloud data acquired in the S2, performing automatic detection processing on appearance features of the track plate in software, performing overlay analysis on the three-dimensional design model and measured point cloud data, and automatically extracting appearance detection items of the CRTSIII-type track plate.