The utility model discloses a combined collection device for straw treatment. The combined collection device comprises a frame body and wheel bodies which are arranged on the two sides of the frame body and drive the frame body to move forwards or backwards. The cab is arranged on the frame body, heat insulation cotton is installed at the upper end of the cab, and anti-noise cotton is embedded inthe heat insulation cotton; the cutting knife is arranged at the front end of the frame body and used for cutting cereals; the reel is arranged on one side, close to the frame body or far away from the frame body, of the cutting knife; the straw collecting device is used for collecting the straws cut off by the cutting knife and the reel by adopting blast airflow; the straw collecting device is used for collecting the cut straws through a pipeline penetrating into the lower parts of the cutting knife and the reel; a plowing part for plowing the land and a storage box for accommodating seeds are arranged at the rear part of the frame body; and the heights of the cutting knife and the reel can be adjusted in the vertical direction. According to the combined collection device for straw treatment, the cutter and the reel are integrated, and switching between the cutter and the reel is conducted according to actual needs.