The invention discloses a respiratory function exercise machine, which comprises a blowing nozzle, an air inlet pipe, a spiral pipe and an exhaust pipe. The spiral pipe is filled with sealing liquid;the length of the sealing liquid in the spiral pipe is equal to the length of the sealing liquid moving for a circle along the spiral pipe; the spiral pipe is horizontally installed; the air blowing nozzle is communicated with one end of the spiral pipe through the air inlet pipe, and the other end of the spiral pipe is connected with the exhaust pipe; the exhaust pipe is provided with a three-wayreversing valve; and the other end of the three-way reversing valve is communicated with an air bag. The invention aims to provide the respiratory function exercise machine which improves air tightness, reduces respiratory resistance and is low in cost. The infrared geminate transistors transmit detected signals to a controller, and the controller judges the position of the sealing liquid, so that the air blowing amount is obtained, and finally, the air blowing amount is directly displayed on the display screen.