In the surgical treatment of many spinal diseases, the active lumbar must be partially fixed and fused to stable sacral structure. The special physiological and anatomical structure of the lumbosacral region determines that the sacrum is the stress concentration area of the internal fixation system. Therefore, the failure of internal fixation often occurs at the sacral side first, and eventually leads to fusion failure, which seriously affects the clinical efficacy. With the development of imaging technology and the deepening of sacral biomechanics research, the Second Sacral Alar Screw (S2AS) technology has attracted more and more attention from spine surgeons because it increases fixation points and strengthens in the sacrum fixation strength on the basis of not crossing the sacroiliac joint, which can avoid the related complications of sacroiliac joint fixation. This paper reviews the domestic and foreign researches on the anatomy, biomechanics, technical points and clinical applications of S2AS technology in recent years, providing reference for orthopedic surgeons and researchers