Abstract: With the continuous development of high sulfur gas reservoirs, the problem of sulfur deposition in sour gas gathering pipeline is increasing highlighted. At present, prediction model for sulfur deposition is not perfect, and there are few dedicated reports on detection method for such sulfur deposition. A new non-intrusive detection method based on ultrasonic echo is proposed. Ultrasonic wave is highly penetrative and may reflect and transmit significantly when encountering the interface. Therefore, the ultrasonic echo at two interfaces (pipe inner wall-sulfur deposition interface, and sulfur deposition- nature gas interface) is monitored to accurately detect the sulfur deposition thickness in pipeline. The numerical simulation shows that the error of sulfur deposition detection with ultrasonic echo is within ±2%. The method is safe and reliable, without damage to the pipeline structure, and it is not affected by pipeline temperature and pressure. The detection results are meaningful for guiding the operation and pigging of sour gas gathering system.