An improved structure of a connection and adjustment assembly of a support socket joint of a prosthesis includes a connector, in which a vertical through hole and a horizontal through hole are formed. A support socket is provided on the connector and receives therein an arrest axle extending through the vertical through hole. The horizontal through hole receives therein a shaft, which has an end having a toothed wheel engageable with the arrest axle and an opposite end to which a second one-way bearing, a sleeve, and a knob cap are mounted. The knob cap has an interior that is an elliptical configuration corresponding to and mating an outside elliptical configuration of the sleeve. Pressing a knob causes movement of the sleeve and thus components mounted to the shaft so as to have the toothed wheel disengage from the arrest axle, allowing the arrest axle to be withdrawn out.
