For "Inflatable Air Blower" who, if designed properly, it may be counter-productive wind phenomenon, namely, the outlet mutual swap. For this reason, in the experimental study conducted simulated tank. dc cross flow fan boundary (case), and cross-flow fan is generally curved GF (rear wall) by a gap between the impeller increases, and an arc-shaped or other shape and the upper boundary of the vortex BD DE tongue formed. "Inflatable Air Blower" volute tongue length of its border with the outlet on the angle γ DE have a greater impact on the fan performance. It was found that when a certain length BD tongue vortex, vortex heart C1 point, the fan to work properly, the fluid flow direction. With the decrease of the tongue and vortex impeller clearance δ of "Inflatable Air Blower", move out the bottom vortex center C1, decreases. The angle γ appropriately reduced, easy fluid outflow along the border, will also make decreases.