The invention discloses an arm movement limiting device which belongs to the technical field of auxiliary medical devices. The arm movement limiting device comprises a fixed supporting plate (1), wherein a fixed groove (2) which is fit with an arm shape is formed on the upper part of the fixed supporting plate (1), and four fixing bands (4) are arranged on the two sides of the fixed groove (2) of the fixed supporting plate (1) along the length direction of the fixed supporting plate (1) at interval. According to the device, the fixed groove with the shape which is fit with the arm shape and the four fixing bands which are arranged on the two sides of the fixed groove are utilized to effectively fix a patient arm, so that a wrist joint and an elbow joint cannot bend, fingers cannot clench, the fixing band compression on arm blood vessels is relieved to the maximum extent, the arm movement can be well limited, the arm blood circulation after using the arm movement limiting device for a long time can be ensured, the serious illness and postoperation nurse difficulty are relieved, and the device is beneficial to the recovery of patients with serious illness and after operation.