The utility model discloses a flexible thin wall bearing test installation axle subassembly, including blind rivet, the bearing installation body and flexible thin wall bearing clamping device, the bearing installation body is including axle form main part, the front portion of axle form main part is provided with the oval axle journal that is used for realizing flexible thin wall bearing radical location, and the rear portion sets up cone part, the blind rivet is connected the setting and is in cone part's end, flexible thin wall bearing clamping device detachably is fixed to be set up oval axle journal both sides for realize flexible thin wall bearing axial positioning. The utility model discloses a to flexible thin wall bearing fixed on the bearing installation body, constituted flexible thin wall bearing test installation axle subassembly, guaranteed the dynamic balancing structure when bearing installation height is fast rotatory, the oval operating condition that warp of flexible thin wall bearing in the harmonic speed reducer ware is particularly useful for simulating, can be connected with high -speed electric main shaft, compact structure, install and remove convenient, the safe and reliable that works, increase the accuracy of test result.