The invention discloses a spraying device comprising a water injection pipe. The two sides of the surface of the water injection pipe are fixedly provided with mounting brackets of inverted-L-shaped structures, the mounting brackets are of a split structure, and a length-adjustable connecting mechanism is arranged between split parts; and the connecting mechanism is composed of four connecting plates connected end to end, four intersection points are formed, two intersection points at the opposite positions are connected with the two split mounting brackets, connecting pins B penetrate throughthe connection positions, and connecting pins A penetrate through the intersection points at the other two opposite positions. Through the designed connecting plates, in the installing process, according to the actual installation situation, the lengths of the mounting brackets are adjusted, and it is ensured that the installing stability is not influenced; and meanwhile, in cooperation with thedesigned connecting pins A and connecting pins B, stability during installation can be increased.