The present invention provides a CT triaxial test apparatus for hydrate-bearing sediment, and belongs to the technical field of fundamental physical property measurement of geotechnical engineering. In the apparatus, aiming at the defects of the invention “a visual test apparatus for mechanical characteristics of natural gas hydrate-bearing sediment”, the CT triaxial test apparatus for hydrate-bearing sediment is redesigned and optimized, on the premise of obtaining static and dynamic mechanical characteristics and creep characteristics of a hydrate reservoir, the stability of the triaxial apparatus during rotation due to scanning, the temperature control accuracy of a hydrate-bearing sample, and the X-ray penetration performance of the pressure chamber of the triaxial apparatus are improved, an optimal CT imaging effect is obtained, and powerful hardware support is provided to ascertain the reservoir deformation mechanism during hydrate decomposition.