The utility model provides an acetabular prosthesis and a hip joint prosthesis. The acetabular prosthesis comprises a cup body, wherein the cup body is hemispherical and provided with a hemispherical accommodating space in the inside, a round opening communicated with the cup body is formed, the sphere center of the hemispherical accommodating space coincides with the sphere center of the hemispherical cup body, the hemispherical inner wall of the cup body defining the accommodating space is provided with a guide hole, and a central line of the guide hole and a central line of the cup body form an inclination angle. The abrasion direction control of the acetabular prosthesis is achieved. When a doctor performs an implanting operation, the doctor can correct deviation in the prosthesis implanting direction by means of positioning of the guide hole during operation. The acetabulum and the sphere center of a ball are kept in a coinciding mode, a stable lubricating state is kept, and the friction coefficient is effectively reduced. In addition, the guide hole enables the thighbone ball to sink relative to the acetabulum position, a gap between the acetabulum and the ball is decreased, an optimal matching gap is re-established through oriented abrasion of the ball and the prosthesis, and accordingly the shortcoming of an overlarge gap between the acetabular prosthesis and the ball is overcome.