The invention relates to a pesticide spray application system and a pesticide spray application method applicable to scale production of wheat and rice.The system comprises a long-distance spraying device, a stirring box and a short-distance spraying mechanism, the long-distance spraying device and the stirring box are installed on a farm truck, the stirring box is filled with pesticide liquid and is communicated with a suction valve of the long-distance spraying device, the long-distance spraying device comprises a drum fan and a centrifugal pump, the short-distance spraying mechanism is installed at the bottom of an air outlet of the drum fan and is connected with the centrifugal pump of the long-distance spraying device, the centrifugal pump is used for centrifugal atomization of the pesticide liquid sucked by the suction valve, and the drum fan and the short-distance spraying mechanism spray the centrifugally atomized pesticide liquid to wheat and rice fields.The pesticide spray application system is wide in pesticide spray application range, uniform in pesticide spray application, higher in pesticide spray application effect, high in atomization degree and saving in pesticide cost.