Objective To investigate the effectiveness of a single threaded anchor fixation under shoulder arthroscopy in the treatment of fresh bony Bankart injury. Methods Between January 2017 and May 2021, 12 patients with fresh bony Bankart injury caused by trauma were treated with a single threaded anchor fixation under shoulder arthroscopy. There were 10 males and 2 females with an average age of 38.8 years (range, 21-64 years). The time between injury and operation ranged from 7 to 30 days (mean, 15.8 days). Preoperative American Shoulder and Elbow Surgeons (ASES) score was 44.9±17.4, the University of California at Los Angeles (UCLA) score was 13.1±5.5; the forward supination, lateral external rotation, and lateral internal rotation of shoulder were (130.8±11.8)°, (25.0±7.9)°, and 9.2±1.6, respectively. CT scan and three-dimensional (3D) reconstruction showed that the fracture fragment area was less than 1/4 of the glenoid area in 10 cases, and 1/4-1/2 in 2 cases. The operation time was recorded. During follow-up, ASES score, UCLA score, Rowes score, and shoulder range of motion were used to evaluate the effectiveness, and shoulder CT scan and 3D reconstruction were used to evaluate the fracture position and healing. Results The operation time ranged from 50 to 150 minutes (mean, 85.5 minutes). All patients were followed up 3-18 months (mean, 9.1 months). There was no serious adverse effect such as infection, re-dislocation, or thrombosis. Three patients had shoulder adhesions after operation. At last follow-up, the forward supination of shoulder [(162.1±30.3)°], lateral external rotation [(37.5±11.2)°], and lateral internal rotation (9.2±1.6) significantly improved when compared with those before operation (t=3.331, P=0.003; t=3.153, P=0.005; t=2.716, P=0.013). The ASES score was 89.7±11.8 and the UCLA score was 32.8±2.4, which significantly increased when compared with those before operation (t=7.368, P<0.001; t=11.370, P<0.001). The Rowes score ranged from 75 to 100 (mean, 92.9). Among them, 9 cases were excellent and 3 cases were good, with an excellent and good rate of 100%. CT re-examination showed that the fracture line disappeared in 11 cases, and the fracture alignment was good; the alignment of the fracture fragment was poor in 1 case whose fracture fragment area was between 1/4 and 1/2 of the glenoid area. Conclusion For the fracture fragment area not exceeding 1/4 of the glenoid, the labrum-capsule complex at the lower end of the bone fragment intact, and the non-comminuted fresh bony Bankart injury, a single threaded anchor fixation under shoulder arthroscopy can achieve better effectiveness, has the advantages of less trauma and faster postoperative recovery.