The invention discloses a cutter radius compensation method based on characteristics. The cutter radius compensation method based on the characteristics is characterized by including the steps of, firstly, carrying out characteristic identification, based on the identification characteristic results, carrying out process decision making on a part, then outputting a cutter path machining file, wherein the cutter path machining file comprises cutter location point information, and further comprises characteristic type information, machining manner information and cutter radius compensation contact point information which are required by cutter radius compensation, inputting the cutter path file into a rear-mounted processing module, determining the cutter radius compensation type according to the characteristic information and the machining manner information, adopting a corresponding cutter radius compensation algorithm to carry out cutter radius compensation on an original APT cutter file, and generating a new matched numerical control machining program, wherein the cutter radius compensation type includes a side milling compensation type, an end milling compensation type and an end-milling and side-milling mixing compensation type, and each compensation type is provided with a corresponding cutter radius compensation algorithm. The cutter radius compensation method based on the characteristics achieves the cutter radius compensation in machining of airplane structural components, and enables the cutter radius compensation of five-axis machining to be more efficient.