The invention discloses a portable shoulder joint self-stretching trainer. The portable shoulder joint self-stretching trainer comprises a handle, wherein a connecting block is arranged at the lower end of the handle, a suction disc is arranged at the lower end of the connecting block, a first convex block is arranged at the lower end of the handle, a through hole is formed in the center of the connecting block, a second convex block is arranged at the upper end of the suction disc, the first convex block and the second convex block are oppositely arranged in the through hole, a groove is formed in the second convex block, and the lower end of the first convex block is arranged in the groove to enable the handle to be connected with the suction disc. In the mode, the portable shoulder joint self-stretching trainer is small in size, low in cost and convenient to use, can be carried about, a patient can use the trainer in a working area at home at any time, and the economical burden of the patient is reduced.