The invention discloses a balloon blowing nozzle. A flat circular mouthpiece of an integrated structure is formed in the left end of the blowing nozzle body, a check valve is arranged at the inner diameter of the right part of the blowing nozzle body, the outer diameter end of the blowing nozzle body at the right end of the flat circular mouthpiece is arranged in a circular through hole of a spherical shield in a penetrating way, an annular slot is formed in the outer diameter end of the blowing nozzle body on the right side of the spherical shield, a rubber snap ring is arranged in the annular slot, and the blowing end of the balloon air bag is clamped into the annular slot by the rubber snap ring after being sleeved on the outer diameter end of the right part of the blowing nozzle body. By utilizing the balloon blowing nozzle, children can easily complete blowing of the balloon, the structure is simple, and the use is safe.