Abstract: The paper introduced spray method, working principle, composition and characteristics of a spray system of hydraulic support of thin coal seam. The spray system of hydraulic support adopts method of high pressure spray method and can control dust around hydraulic support of thin coal seam in coal face effectively. The spray device is set in roof timber in order to save space, which resolves the problem that spary device occupies walkway and cross section of ventilation. The system takes full advantages of electro hydraulic controller and has high automation degree.