Objective: To evaluate the diagnostic value of high frequency Color Doppler Ultrasound (CDU) and electromyography in Carpaltunnel syndrome (CTS). Methods: 80 patients with CTS admitted to our hospital from May 2022 to May 2024 were selected as the study group. At the same time, 80 healthy subjects who underwent physical examination in our hospital during the same period were selected to be included in the control group. Both groups were examined by high-frequency CDU and EMG, respectively. The results of high-frequency CDU and EMG were compared between the two groups. To analyze the diagnostic value of high-frequency CDU and electromyography in CTS. Results: The left and right diameters, anterior and posterior diameters, Cross-sectional area (CSA) and motor latency (DML) at the end of median nerve were significantly higher in the study group than in the control group (P < 0.05). Compound muscle action potential (CMAP) and Sensory nerve conduction velocity (CMAP) of median nerve SCV and Sensory nerve action potential (SNAP) were significantly lower than those of control group, and the specificity and accuracy of high-frequency CDU in diagnosing CTS were significantly higher than those of electromyography (P < 0.05). There was no significant difference in diagnostic sensitivity between high-frequency CDU and EMG for CTS (P > 0.05). Conclusion: Compared with EMG, high-frequency CDU can accurately detect CTS, and high-frequency CDU can effectively display the shape, structure, and course of the median wrist nerve of CTS patients and identify the cause.