A limb prosthesis including a palm, a forearm, an upper arm, an elbow joint and a wrist joint is provided. The palm has a first pivot and a first lock set. The upper arm has a socket. The elbow joint connects the forearm to the upper arm. The wrist joint includes a first connecting rod connected to the forearm. The first pivot rotatably penetrates through the first connecting rod. The first lock set is locked to the first pivot. A first wedge surface of the first lock set contacts a second wedge surface of the first connecting rod. By adjusting a distance between the first lock set and the first pivot, a magnitude of a forward force between the first wedge surface and the second wedge surface is adjusted, such that the palm is fixed relative to the first connecting rod or rotatable around an axial direction perpendicular to an extending direction of the forearm.