The invention discloses a center-adjustable ball spherical hinge joint and a center adjusting method of the center-adjustable ball spherical hinge joint. Due to machining and assembling errors, a spherical hinge joint is in an eccentric state usually. Supporting ball guide holes are formed in a supporting ball socket of the ball spherical hinge joint. A displacement sensor is installed in a sensor installation hole of the supporting ball socket. Restraining ball guide holes are formed in a restraining ball socket. Double-thread center adjusting mechanisms are installed in the supporting ball guide holes and the restraining ball guide holes to adjust ball steel balls. The center adjusting method includes the steps that the center-adjustable ball spherical hinge joint is installed; when the double-thread center adjusting mechanisms are installed, main threaded columns and auxiliary threaded columns rotate in the opposite directions, and the restraining ball steel balls and the supporting ball steel balls are quickly located; and when centering adjustment is conducted by the double-thread center adjusting mechanisms, the main threaded columns and the auxiliary threaded columns rotate in the same direction. The double-thread structures rotate in the opposite directions when the eccentric error is relatively large, and the eccentric error is quickly reduced; and the double-thread structures rotate in the same direction when the eccentric error is relatively small, and the centering condition of the balls and the ball sockets are finely adjusted.