Objective:To observe any effect of combining ultrasound-guided drug injection into the subacromial bursa, coracoid bursa and shoulder joint cavity with hydraulic dilation of the glenohumeral joint in the treatment of frozen shoulder (FS).Methods:A total of 116 persons diagnosed with FS were randomly divided into an injection treatment group and a combined treatment group, each of 58. On the first day, both groups received ultrasound-guided steroid injections into the subacromial bursa, coracoid bursa and shoulder joint cavity. The combined treatment group was also injected with 30ml of normal saline into the glenohumeral joint for hydraulic dilation. All then followed a family-based program of shoulder function training for 15 days. Shoulder pain assessment (VAS) and shoulder function assessment (PROM) were performed for both groups before the treatment, after the injections and after the shoulder function training.Results:The average VAS and PROM scores of both groups were significantly different after the treatment, with those of the combined treatment group significantly better than the injection group′s averages at each time point.Conclusion:Combining ultrasound-guided drug injection with hydraulic dilation of the subacromial bursa, the coracoid bursa and the shoulder joint cavity can significantly relieve pain of FS and improve shoulder mobility. It is more effective than drug injection alone.