Under the action of catastrophic earthquake, the nodes of grid structure soften due to the accumulation of damage, which has a great influence on the overall structural performance. To study the failure forms of transition plate bearing joints during ultra-low cycle fatigue test, a bidirectional loading test device was designed for bearing joints, and ultra-low cycle fatigue test was carried out for bearing joints, the failure process of the anchor bolt was studied, and the variation rules of the anchor bolt's inclination angle and the overall rotation Angle during the loading process were obtained. The results show that the failure forms of the transition plate bearing node in the test process are all anchor bolt fracture, and the anchor bolt fracture has obvious ultra-low cycle fatigue failure characteristics. The changes of anchor bolt inclination angle and overall rotation angle of the bearing node can reflect the degree of anchor bolt damage in the bearing node, which can provide a reference for evaluating the state of the bearing node after earthquake.