Objective To assess the dynamic evaluation of high frequency ultrasound for carpal tunnel syndrome after transverse carpal ligament release with arthroscopy. Methods The study included 31 patients (44 wrists) with a definitive diagnosis of CTS. The edema range of median nerve at entrapment proximal, diameter and cross-sectional area of median nerve at the inlet of the carpal tunnel were detected by high frequency ultrasound at 3 days preoperative, 2 weeks, 4 weeks, 3 months, 6 months, 1 year postoperative separately. ROC analysis of high frequency ultrasound was performed. Results The neuroanatomical parameters were gradually improved postoperative. All the neuroanatomical parameters were improved significantly during 1 month to 3 months after surgery. High frequency ultrasound has high diagnostic efficacy for CTS. Conclusion High frequency ultrasound has effective dynamic value in neuroanatomical parameters for carpal tunnel syndrome after transverse carpal ligament release with arthroscopy.