The utility model relates to an inner tube support technical field is a guarantor's type inner tube cutting device, including right branch frame and left socle, right branch frame semiorbicular backing ring, a left side keep off the semi -ring, the right side keeps off semi -ring, bracing piece and base including being, the left socle make progress rectangular form and roll seat, roller, bracing piece and base including being the opening. The utility model has the advantages of reasonable and compact structure, through using semiorbicular backing ring to support guarantor's type inner tube, can make its no longer back -and -forth movement, progradation through the roller can labour saving and time saving, does not so need artifical installation guarantor type inner tube, has reduced intensity of labour, has more effectively improved work efficiency, with using the protective sheath to pack it after guarantor's type inner tube segmentation cutting, scattering so that shaping in the rock core type inner tube in insurance validity of rock core has been reduced to use mode messenger rock core shaping such as freezing, so that the core analysis in later stage and chemical examination work.