Objective To explore the effect of robotic training under position limitation on upper limb of patients with shoulder sub-luxation after stroke. Methods From March to December,2023,sixty patients with shoulder subluxation after stroke in the First Affiliated Hospital of Bengbu Medical University were randomized into conventional group(n = 20),robot group(n = 20)and position-limited group(n = 20).All the groups accepted conventional rehabilitation,while the robot group underwent robot training and the position-limited group underwent robot training under position limitation,for four weeks.Before and after treatment,Fugl-Meyer Assessment-Upper Extremities(FMA-UE)and modified Bar-thel Index(MBI)were used for evaluation,surface electromyography(sEMG)was used to measure the average electromyography(AEMG)and root mean square(RMS)of posterior deltoid fasciculus and supraspinatus during contraction,and musculoskeletal ultrasonography was used to determine the distance of acromion-greater tuber-osity(AGT)of the affected side. Results After treatment,FMA-UE score,MBI score,AEMG,RMS and the distance of AGT improved in all the groups(|t|>10.850,P<0.001),and all the indexes were optimal in the position-limited group(F>42.031,P<0.001). Conclusion Robotic training for upper limb under postural limitation can further improve upper limb function and sub-luxation status,activities of daily living,and peri-shoulder muscle in patients with shoulder subluxation after stroke.