The water power ejector is merit of innovation manufacture the synthesis domestic similar product is one kind has pulls out the vacuum, the condensation, draining water and so on three kind of mechanisms. Its principle of work is the use certain pressure current of water becomes the certain gradient through the symmetrical even cloth the blowout, gets together on a focal point, because sprays the velocity of flow to be higher, thereupon periphery forms in the negative pressure causing room the cavitation. Moreover because two steam with spray the fluent direct contact, carries on the heat change, the major part steam congeals the water, the small amount not by the condensation steam with the gas which does not congeal also because with high speed sprays the current of water mutually to rub, the mix extrusion, through expands the pressure tube to remove, in the causing room forms a higher vacuum. The water power ejector divides the cast iron and the stainless steel two kind of material qualities, the application extremely widespread, mainly is suitable to the vacuum with evaporates the system, carries on vacuum evaporation, the vacuum pumps water, the vacuum crystallizes, is dry, craft and so on air sweetening, is the system sugar, the drugs manufacture, the chemical industry, food, the salt-making, the monosodium glutamate, the milk, the fermentation, brews, the light industry, the national defense department widespread need equipment.