The invention discloses a pelvis mechanism for gait rehabilitation training. The mechanism comprises a base, a rocker, a junction box, a cover plate, a swing member, an extension shaft, a supporting plate, a supporting arm and the like, wherein the base can move up and down along a stand column of a robot to realize the degree of freedom for vertical movement at the pelvis; the junction box can swing left and right around the base through the rocker to realize the degree of freedom for left-right movement at the pelvis of a patient; the swing member can rotate around the junction box through two joint ball bearings to meet the twist motion, roll motion and pitching motion of the pelvis. According to the pelvis mechanism, the constraint to the patient can be effectively reduced, so that the patient can freely move the pelvis, the comfort of the training process is improved, the balance capacity is trained while the lower limb walking function is trained, and a better training effect is achieved.