Abstract: A rock mass shear test system for high-energy accelerator computed tomography (CT) scanning includes double horizontal loading devices, a first bearing device for bearing a static shear box, a second bearing device for bearing a dynamic shear box, and a normal loading device, etc. In the test, the double horizontal loading devices simultaneously apply an identical loading force to the rock mass, and the normal loading device applies a shear force to the rock mass. The double horizontal loading devices are provided in parallel and spaced apart, a loading force is applied in the horizontal direction, and a shear force is applied in the vertical direction, so that the loading cylinder and the rock mass sample are effectively prevented from interfering with each other during the accurate scanning process of the shearing progressive failure process of the rock mass.