Abstract: The JSB5-L wet concrete spraying unit is composed of nine large parts, all of which are controlled by hydraulic system and can be used in coal mine with gas and so on. In this paper, the unit production capacity, rebound rate, injection strength and other basic performance tests have reached the design and specification requirements. At the same time, the concrete injection test was conducted to ensure the reliable operation of the system and to improve the cooling system so that the oil temperature was controlled within the normal operation range of the machine.