According to the actual situation of higher energy consumption, as well as the greater fluctuations of yield and unstable feed quantity of suction nozzle in pneumatic conveying, the mechanism of airflow disturbance was analyzed. The grain suction nozzle of airflow disturbance was designed by using return air of positive pressure of pneumatic conveying as disturbed gas source, which could increase mixture between grain and airflow of grain inlet, by helping grain entering system and energy transmitting as well as converting. The use of separator of large curvature elbow had advantages of one wind multipurpose, including anti-collision, anti-broken, dust removal, energy saving and loss reduction. Results showed that the output of pneumatic conveying and efficiency of fan were the highest when the disturbed gas flow was 11%～13% of fan air volume, with the velocity of airflow disturbance at 16～18 m/s.