Abstract: In view of problems that current dust suppressant spraying system of train has low equipment safety and poor quality of dust suppression operation, a precision control system for train dust suppressant spraying based on ultrasonic space identification was designed, and corresponding software control flow of the system was given. The system uses ultrasonic detection device to precisely control coal dust suppression spraying arm of train, which can effectively avoid other locomotive, identify materials or vehicle load conditions, and improve quality of spraying.