To install other cassette for presetting a tool in a quick-replacement cutting tool cassette outside a device and operating a cutting device simultaneously with preset work.

This cutting tool preset system removes a cutting tool cassette 1 provided in connection with a rotating cutting head therefrom and places it on another preset frame 12 for matching. The present frame 12 is provided with a fixing and central matching means 13 for a tube or a shaft 14 and a reference surface 15 located at a prescribed position relative to a member which is inside the cutting head and operates a cutting wheel 4. Regulating device 5, 6 for the cassette 1 placed on the preset frame 12 set the cutting wheel 4 at a desired initial machining distance from the surface of a tube or the shaft 14 based on the reference surface 15.