The utility model provides a water spraying device of block grinding equipment. The water spraying device comprises a water pump and a water spraying structure capable of being fixed on the block grinding equipment. The water spraying structure comprises a water inlet end and a water outlet end, wherein the water inlet end of the water spraying structure is communicated with a water outlet of the water pump through a pipeline. When used, the water spraying device is fixed on the block grinding equipment, the position of the water outlet end of the water spraying structure is adjusted so that the water outlet end right faces a block grinding portion. Water is pumped from a water tank by means of the water pump, enters the water spraying structure through a pipeline, and flows out from the water outlet end of the water spraying structure to lower temperatures of a grinding piece and a block and to wet dust generated during grinding. Water supply continuity of the water spraying device is strong, the water spraying device does not need to be manually held and operated, and use is safe. Compared with the prior art, the water spraying device is large in water outflow pressure, can reduce water outflow amount on the condition that identical temperature lowering and dust removing effects are achieved, and therefore more water is saved.