The invention relates to a shoulder joint abduction fixation orthotic device. The shoulder joint abduction fixation orthotic device comprises a forearm support frame, a C-shaped upper arm bracket, an armpit support frame, a line-shaped armpit movable shaft and an adjustable support. The forearm support frame, the C-shaped upper arm bracket and the armpit support frame are integrally formed and used for supporting the forearm, the upper arm and the armpit on one side respectively, the line-shaped armpit movable shaft is arranged between the C-shaped upper arm bracket and the armpit support frame, and the adjustable support with one end connected with the C-shaped upper arm bracket and the other end connected with the armpit support frame is used for adjusting the shoulder joint abduction angle. The shoulder joint abduction fixation orthotic device can effectively overcome the defects of an existing orthotic device and ensure the postoperative effect of shoulder periarticular operations.