A joint module of a robot arm, wherein the joint module comprises: a housing; a driving assembly, comprising a lower bearing seat, a lower bearing having an outer ring connected with the lower bearing seat, and an output shaft connected with an inner ring of the lower bearing; a speed reduction assembly, comprising an input shaft detachably connected with the output shaft; a braking assembly, connected with the output shaft; a first fastener, configured to fix the lower bearing seat on the housing; and a second fastener, configured to fix the speed reduction assembly on the housing; the driving assembly further comprises: an upper bearing seat, arranged on a side of the lower bearing seat opposite to the speed reduction assembly, and the braking assembly being fixed on the upper bearing seat; and an upper bearing, comprising an inner ring connected with the output shaft and an outer ring connected with the upper bearing seat; characterized in that, the joint module further comprises: a first elastic member; wherein the braking assembly is configured to press the first elastic member on the outer ring of the upper bearing; the braking assembly comprises a friction plate connected with the output shaft, and the driving assembly further comprises an adapter connected with the output shaft; wherein the friction plate is sleeved on the adapter, an outer contour of the adapter and an inner contour of the friction plate are non-circular and matched with each other when viewed along an axial direction of the output shaft, to allow the friction plate to rotate with the adapter, and allow the friction plate to move relative to the adapter along the axial direction of the output shaft. a housing; a driving assembly, comprising a lower bearing seat, a lower bearing having an outer ring connected with the lower bearing seat, and an output shaft connected with an inner ring of the lower bearing; a speed reduction assembly, comprising an input shaft detachably connected with the output shaft; a braking assembly, connected with the output shaft; a first fastener, configured to fix the lower bearing seat on the housing; and a second fastener, configured to fix the speed reduction assembly on the housing; the driving assembly further comprises: an upper bearing seat, arranged on a side of the lower bearing seat opposite to the speed reduction assembly, and the braking assembly being fixed on the upper bearing seat; and an upper bearing, comprising an inner ring connected with the output shaft and an outer ring connected with the upper bearing seat; an upper bearing seat, arranged on a side of the lower bearing seat opposite to the speed reduction assembly, and the braking assembly being fixed on the upper bearing seat; and an upper bearing, comprising an inner ring connected with the output shaft and an outer ring connected with the upper bearing seat; characterized in that, the joint module further comprises: a first elastic member; wherein the braking assembly is configured to press the first elastic member on the outer ring of the upper bearing; the braking assembly comprises a friction plate connected with the output shaft, and the driving assembly further comprises an adapter connected with the output shaft; wherein the friction plate is sleeved on the adapter, an outer contour of the adapter and an inner contour of the friction plate are non-circular and matched with each other when viewed along an axial direction of the output shaft, to allow the friction plate to rotate with the adapter, and allow the friction plate to move relative to the adapter along the axial direction of the output shaft.