To provide a cylinder cutting device capable of cross-cutting a cylinder (e.g., PEEK resin tube) easily and surely at a cutting angle (e.g., 20 to 70°) not perpendicular to its longitudinal direction.

The cylinder cutting device includes a base and a cutting blade, and pushes to cross-cut a cylinder at a cutting angle not perpendicular to its longitudinal direction. Preferably, the base is a rectangular column, its side face has a through-hole through which the cylinder to be cut is inserted, and the cutting device cuts the cylinder with its inserted state into the through-hole. The base is the rectangular column, a mounting groove is formed on its upper surface, and the cutting device cuts the cylinder with its mounted state on the mounting groove.