The invention provides a water 
emulsion pesticide system capable of substituting for the traditional 
oil emulsion. The 
system comprises the following raw materials by weight percent: 0.5-60% of crude 
pesticide or 
pesticide crude oil, 0.5-5% of 
macromolecule emulsifier, 0.5-10% of micromolecule emulsifier, 0-15% of cosolvent, 0-5% of 
adjuvant and the balance of deionized water, wherein the 
macromolecule emulsifier is an amphiphilic 
polymer which is formed by polymerizing a component 1, a component 2 and a component 3 at a 
mole ratio of 1:(0.05-0.5):(0-0.5) and is in a micro-crosslinked structure; the 
viscosity of the 1% deionized water dispersion of the 
polymer is between 100 mPa.s to 10000 mPa.s at PH value of 5-9 and 25 DEG C, and a relative molecular weight of the 
polymer is between 0.5million to 20 million; the component 1 is 
acrylic acid or acrylic ester with carbon molecular number not more than 36; the component 2 is alkenyl 
ammonium chloride with carbon molecular number not more than 25; and the component 3 is allyl 
amide with carbon molecular number not more than 5. The water 
emulsion pesticide 
system provided by the invention enables the crude pesticide with tiny 
solubility in water, oil or organic solvents to form the water 
emulsion with 
low toxicity, high efficiency, and good stability. The invention further provides a preparation method of the water emulsion pesticide.