Contrast with ground spraying, aerial spraying has the advantages of mobility, flexibility and efficiency.So aerial spraying received serious attention in recent years, and become the developing direction of the crop protection.There are many effecting factors of spraying effect,such as aircraft model, nozzle model, sprayer pressure, spraying angle, meteorological condition (temperature, humidity, wind speed, wind direction), operation height, operation speed, reagent combination, reagent concentration, and so on.These factors affect the deposition character of the droplets on the plants surface, and then affect the spaying effect ultimately.The droplets distribution characteristics is the main factor to determine the effect of aviation plant protection.To research the droplet distribution under the condition of different factors can provide reference to choose a relatively suitable nozzle model, spraying pressure, spraying angle, operation height,operation speed, reagent combination, reagent concentration, its very important for ensuring applying pesticide effect.This paper is based on in-depth analysis of the status of aerial spraying of plant protection, and then it pointed out the main problems exist in Chinas agricultural aviation of plant protection are as follows: (1) Different operation parameters(operation height, operation speed) will influence the spraying effect;(2) Different meteorological conditions will influence the spraying effect;(3) Different nozzle parameters will influence the spaying effect;(4) Different reagent combination and reagent concentration will influence spraying effect.But there is no operation instruction regulations for aerial aviation spraying for plant protection in China.So, in this paper, authors pointed out the methods of aviation technical specification of plant protection and the establishment of decision support system for major crops (Rice and Cotton) in China.Its purpose is to provide a theoretical basis and decision support guidance for aerial spraying in our country.