Objective To observe the effect of extracorporeal shock wave therapy combined with conventional rehabilitation in the treatment of hemiplegic shoulder pain (HSP). Methods HSP patients admitted to Huadong Hospital Affiliated to Fudan University between January and October 2022 were selected. The enrolled patients were randomized into a control group and an experimental group in a 1∶1 ratio using SPSS 26.0 statistical software. The control group was given conventional rehabilitation training, and the experimental group was given extracorporeal shock wave treatment on this basis. Both groups were treated for 4 weeks. Primary outcome measure was Visual Analogue Scale (VAS) for pain. Secondary outcome measures were passive range of motion (PROM) of the shoulder joint, Fugl-Meyer Assessment of Upper Extremity (FMA-UE), and the activities of daily living were assessed by Modified Barthel Index (MBI). Results A total of 39 patients were included. Among them, there were 19 cases in the experimental group and 20 cases in the control group. Before treatment, there was no statistically significant difference in VAS, FMA-UE, MBI scores, and the PROM of flexion, extension, abduction, external rotation and internal rotation between the two groups (P>0.05). After treatment, there was no statistically significant difference in MBI score and the PROM of extension, abduction, external rotation, internal rotation between the two groups (P>0.05). After treatment, intra group comparisons showed that the VAS, FMA-UE, MBI scores, and the PROM of flexion, extension, abduction, external rotation, and internal rotation of the two groups were better than before treatment (P<0.001). After treatment, inter group comparison showed that the the VAS score in the experimental group was lower than that in the control group (t=5.291, P<0.05), while the FMA-UE score and the PROM of flexion in the experimental group were higher than those in the control group (t=−4.008, 3.164, P<0.05). Conclusion Extracorporeal shock wave therapy can significantly reduce the pain degree of patients with HSP and improve upper limb function and activities of daily living.