A cross-flow impeller mounting structure includes a housing and an impeller shaft support structure mounted on the housing and adapted to mount and support one end of a cross-flow impeller shaft away from a motor; the housing is adapted to mount a cross-flow impeller and match the cross-flow impeller to form an air duct; the housing includes: a side wall; a first end wall connected to one end of the side wall and provided with a first mounting through hole having an aperture which matches an outer diameter of the motor driving the cross-flow impeller to rotate and is adapted to mount the motor; a second end wall connected to the other end of the side wall and provided with a second mounting through hole for the cross-flow impeller to mount; the second end wall, the first end wall and the side wall encloses a cavity receiving the cross-flow impeller.