The invention discloses a joint bearing testing device which comprises a joint bearing, a central spindle and a load and is characterized by further comprising a main rotary liner, a left shaft sleeve, a right shaft sleeve and rolling bearings, wherein the central spindle passes through an inner ring hole of the joint bearing; both ends of the central spindle are respectively sleeved with the leftshaft sleeve and the right shaft sleeve; the left shaft sleeve and the right shaft sleeve are respectively sleeved with the main rotary liner; an axial screw hole is formed outside the left shaft sleeve or the right shaft sleeve; a tensioning screw passes through the screw hole to push the central spindle inside the left shaft sleeve or the right shaft sleeve; both ends of the main rotary liner are respectively mounted on a test stand by the rolling bearings; and the load is loaded to an outer ring of the joint bearing. According to the invention, by transition of the main rotary liner and the left and right shaft sleeves, high-rigidity supporting is provided for the central spindle, a loaded bending degree of the central spindle is minimized, a working condition is the mostly approximateto an only sheared working condition, and the service life of the central spindle is prolonged.