Venturi tube assembly and fan

The utility model provides a venturi tube assembly and a fan. The Venturi tube assembly comprises a Venturi tube body, a negative pressure tapping nozzle, a positive pressure tapping nozzle and an adjusting wheel. The Venturi tube main body comprises an air inlet part, a throat part, an air outlet part and a wind shield which are sequentially connected, the wind shield is arranged at the end, away from the throat part, of the air inlet part, and a first through hole is formed in the wind shield; the negative pressure tapping nozzle is communicated with the throat part; the positive pressure tapping nozzle and the negative pressure tapping nozzle are arranged in parallel; the adjusting wheel is connected to the air baffle and provided with a second through hole, and the air inlet amount of the air inlet part is adjusted by adjusting the overlapping area of the second through hole and the first through hole. The air inlet part of the Venturi tube assembly is provided with the air baffle with the first through h