In order to solve some matters on residual seeds on header and clean the header during harvesting grain seed on the plot by using combine harvester of grain, an air blowing header, by that front airflow bent wheat and then cutter knife cut the wheat stalk, was designed. A blowing cereal model with uniform air flow velocity was established according to mechanics principle. The calculated air flow velocity of branch pipe outlet was more than 47.35m/s under condition of the cut wheat smoothly entering into the harvester header without dropping. According to the theory of static regain design method of multiplebranch duct system, these calculated main structure parameters of airflow pipe which generated uniform air flow in each branch pipe were taper of air flow main pipe of 1∶14.29 and interval distance of air flow branch pipe of 100mm. Three key parameters, including vertical and horizontal distances between cutting knife and air flow branch pipe outlet, the angle between air flow branch pipe and level, that affected header residual amount and total loss rate, were regarded as experimental factors for conducting single factor and multi-factors orthogonal experiments. The single factor experiments showed that the total loss rate of header with firstly increase and then decrease was made by the vertical and horizontal distances between cutting knife and outlet of air flow branch pipe within a scope of 15~27cm.The residues on the header were little affected by horizontal distance between cutting knife and outlet of air flow branch pipe causes. But there was larger effect on the residues on the header for the vertical distance between cutting knife and outlet of air flow branch pipe. The higher the vertical distance was, the more residues were, and even wheat ear was left. The residual and total loss rate of header slowly decreased in 0°~10°, but rapidly increased in 10°~20°, which was made by the angle between air flow branch pipe and level. The orthogonal experiments demonstrated that the effect of the angle between air flow branch pipe and level on total loss rate of header and residual amount was the greatest. The vertical distance between cutting knife and outlet of air flow branch pipe was 21cm, horizontal distance between cutting knife and outlet of air flow branch pipe was 21cm,and the angle between air flow branch pipe and level of 10° was the optimal orthogonal experiments combination. The total loss rate was 0.88% and the header residue was 1.21g under the optimal orthogonal experiments combination. The developed air blowing header with small header residual amount and low total loss rate achieved the technical requirements of the plot harvesting wheat seed.