The utility model discloses a mandrel assembly with stable air blowing function in an injection blow molding machine, comprising: a mandrel body, a mandrel head, a thimble, a pressure spring and a star nut. A rectangular annular air-permeable insert is hermetically arranged in a rectangular air outlet of the mandrel body, a first wedge surface and a second wedge surface are arranged on the air-permeable insert, a third wedge surface is arranged on the mandrel head, a rectangular exhaust piece is hermetically and movably clamped in the rectangular air outlet, a plurality of exhaust grooves are uniformly distributed on the outer side wall of the rectangular exhaust piece, a fourth wedge surface is arranged on the rectangular exhaust piece, the rectangular exhaust piece is connected with the mandrel head, the thimble is movably arranged in the mandrel body and then connected with the rectangular exhaust piece, the pressure spring is sleeved on the thimble, and the star nut is threadedly connected to the thimble and presses against the pressure spring. The utility model can improve the positioning accuracy between the mandrel head and the mandrel body, and can improve the blow molding quality by stabilizing the airflow pressure of compressed air and improving the flow uniformity of compressed air.

Country Code: CN

Application Number: CN202421875479.9