The invention discloses a testing device of the bearing service life. The device comprises a heating tank, a drive sleeve and a power device which can drive the drive sleeve to rotate, wherein the heating tank comprises a bearing chamber, a bearing positioning sleeve arranged in the bearing chamber and a temperature-control system for controlling the temperature of the heating tank, a sleeve through hole through which the drive sleeve can penetrate is arranged on the heating tank, and the sleeve through hole and the bearing positioning sleeve are coaxial. During usage, the outer ring of a bearing to be tested is fixed to the bearing fixing sleeve, the inner ring of the bearing to be tested is fixed to the drive sleeve, the power device drives the drive sleeve to rotate, the bearing rotates under the drive of the drive sleeve, the temperature-control system controls a heater, the environment temperature in the bearing chamber maintains within a required time zone, the bearing to be tested works at the environment temperature, the service life of the bearing to be tested is detected, and the service life of the bearing can be detected on the condition close to an actual use condition.