The invention relates to a sealed rubber mixing mill dust smoke gas collecting and improving method. The pipe diameter of an exhaust pipe is changed; the exhaust pipe is connected with an upper jacking bolt air outlet flange opening; a sealed in-cavity extraction method is realized; positive pressure of dust and smoke gas in an internal mixer load pressing cavity is changed into negative pressure;through such conversion, the flowing direction of airflow inside and outside the cavity can be changed; the previous outward flowing becomes the existing inward suction; during the material feeding and discharging of an internal mixer, a centrifugal fan maintains the operation at the rated hertz; the operation at the 1/4 rated hertz is maintained in other time. The flowing direction of the airflow inside and outside the cavity is changed; the previous outward flowing becomes the existing inward suction. Therefore a draft fan can reduce the 3/4 of the flow rate at the same full pressure; freshair cannot be directly sucked away; the waste gas is also concentrated; the waste gas generating quantity is also saved by more than 3/4; meanwhile, the effect of improving the peripheral environmentof a material feeding door is also achieved.