Abstract: The present invention discloses an automatic sandpaper replacement device for CNC production line, comprising an automatic sandpaper supply mechanism which comprises a bracket assembly, and a sandpaper receiving assembly and a sandpaper extracting plate disposed on bracket assembly; and an automatic sandpaper peeling mechanism that is mated with bracket assembly, and comprises a mounting plate, and a peeling drive assembly and a peeling assembly mounted on mounting plate; wherein peeling assembly is drivingly connected with peeling drive assembly, peeling assembly periodically peels off waste sandpaper on a sanding head under driving of peeling drive assembly, and sandpaper extracting plate periodically supplies new sandpaper to sanding head after peeling off sandpaper.