The invention relates to a medical arm massage device capable of alleviating pain. The medical arm massage device comprises a mounting round plate, wherein four top columns are symmetrically welded to the inner wall of the mounting round plate, a massage sliding block is mounted on the top ends of the four top columns, two L-shaped connecting columns are symmetrically arranged on the upper and lower ends of the massage sliding block, respectively, the two L-shaped connecting columns are symmetrically connected to the back of an arc-shaped massage plate, a connecting shaft is arranged in the middle of the back of the arc-shaped massage plate, six elastic massage branched chains are uniformly arranged along the axial direction of the connecting shaft, the top ends of the six elastic massage branched chains are mounted on the right end surface of an expansion plate; five No.3 hydraulic cylinders are uniformly mounted on the right end surface of the massage sliding block, and the top ends of the five No.3 hydraulic cylinders are mounted on the left end surface of the expansion plate. According to the medical arm massage device, the uniform automatic massage function for the arm can be realized, the pain of the arm is alleviated, in addition, the medical arm massage device has the advantages that the massage force is adjustable, the application range is wide, the massage force is uniform, the massage effect is good, the operation is simple and convenient, the work efficiency is high, etc, and therefore, a novel path for arm massage is provided.