Objective To investigate the effectiveness of arthroscopic double fixation and enhanced suture of long head of biceps tendon (LHBT) in situ for repairing rotator cuff tear. Methods A retrospective analysis was conducted on 31 patients with rotator cuff tears and LHBT injuries admitted between June 2022 and November 2023. All patients underwent arthroscopic double fixation and enhanced suture of LHBT in situ. There were 12 males and 19 females, with an average age of 61.6 years (range, 53-76 years). There were 10 cases of acute injury and 21 cases of chronic injury. According to DeOrio and Cofield classification criteria, the degree of rotator cuff tear rated as medium-sized tears in 3 cases, large tears in 12 cases, and massive tears in 16 cases. Associated injuries included 5 cases of shoulder joint adhesions, 12 cases of subscapularis muscle tears, and 31 case of shoulder impingement syndromes. The shoulder range of motion (ROM) (forward flexion, abduction, lateral external rotation, lateral internal rotation) and pain/function scores [visual analogue scale (VAS) score, University of California Los Angeles (UCLA) shoulder score, Constant-Murley Score] were recorded before operation and at last follow-up. MRI at last follow-up were taken to evaluate the rotator cuff healing and structural integrity. Results All 31 surgeries were successfully completed with operation time ranging from 90 to 210 minutes (mean, 144 minutes). The 3-5 anchors (mean 3.8) were used during operation. All Incisions healed by first intention. All patients were followed up 12-29 months (mean, 18.5 months). At 3 months after operation, 2 cases developed joint adhesions, 3 had internal rotation limitations, and 2 experienced residual pain at the intertubercular groove, all resolved with conservative management. No Popeye deformity occurred during follow-up. At last follow-up, Shoulder ROM (forward flexion, abduction, lateral external rotation, lateral internal rotation) and pain/function scores (VAS, UCLA, and Constant-Murley scores) showed significant improvement compared to preoperative values (P<0.05). At last follow-up, MRI evaluation that the rotator cuff healing rate reached 90.3% according to the Sugaya classification criteria. LHBT exhibited normal morphology, course, and continuity without dislocation. Surrounding synovial sheath showed no thickening or effusion. Conclusion Arthroscopic double fixation and enhanced suture of LHBT in situ for repairing rotator cuff tear can significantly reduce shoulder joint pain, improve ROM, and achieve a high rotator cuff healing rate.