To provide a cutting method for a tubular member and its device capable of preventing generation of burrs on a cutting surface.

In this cutting method for the tubular member, both sides of a section of the tubular member 10 to be cut are respectively held by two holding parts 112 and 132, a disk shaped blade tool 123 is rolled to a circumferential direction of the tubular member 10 while the blade tool 123 is pushed to a center side of the tubular member 10, and the tubular member 10 is cut. In the end of cutting by the blade tool 123, one side 132 of the two holding parts 112 and 132 is relatively rocked to the circumferential direction of the tubular member 10 with respect to the other side 112.