A TBM-mounted surrounding rock wear resistance testing system and method, the system including: a fixing module, arranged on a TBM, the module has a movable end for extending to the surrounding rock of a tunnel; a surrounding rock polishing module on the movable end, the module includes a polishing mechanism for test area; a surrounding rock wear resistance testing module on the movable end, follows the movable end moving the test area, and including a mechanism for testing the wear resistance of the polished test area and a drive mechanism thereof; and a central control module, configured to control the motion states and operations of the fixing module, the surrounding rock polishing module and surrounding rock wear resistance testing module, and determine the wear resistance of the surrounding rock according to the wear resistance test result. The system can polish tunnel surrounding rock during TBM excavation and test wear resistance.