Ball hinge capable of detecting spatial revolution angle

The invention discloses a ball hinge capable of detecting a spatial revolution angle. A traditional ball hinge is complex in angle measurement way and difficult to ensure high measurement precision. A ball socket annular slot is formed in a ball socket of the ball hinge; two ball head annular slots are formed in a ball head; four sliding block components are arranged between the ball socket and the ball head, and each sliding block component comprises a pin shaft and two arc-shaped sliding blocks which are supported at two ends of the pin shaft through a bearing; the arc-shaped sliding block at the outer end of each sliding block component is in sliding connection with the ball socket annular slot, and the arc-shaped sliding block at the inner end of each sliding block component is in sliding connection with the corresponding ball head annular slot; first grid-like cylindrical surface capacitance electrodes are arranged at bottoms of the ball socket annular slot and the ball head annular slot, and a second grid-like cylindrical surface capacitance electrode and a third grid-like cylindrical surface capacitance electrode are arranged at the outer end of the arc-shaped sliding block which is opposite to the ball socket annular slot and at the inner end of the arc-shaped sliding block which is opposite to the ball head annular slot; and voltage is loaded on the first grid-like cylindrical surface capacitance electrodes. The ball hinge disclosed by the invention can realize online measurement of the spatial angle of the ball hinge in three degrees of freedom.