NOVELTY - Prolonging method of foliar fertilizer of chemical auxiliary agent to effective period involves: taking 200-400-mesh plant straw ash, fly ash, attapulgite and lignin according to 2-4:1-2:1-3:1-2 weight ratio, uniformly mixing to obtain composite material; adding the composite material to prepare into solution; adding water into gamma-aminopropyl triethoxysilane by turbid liquid, removing the supernatant fluid, crushing rest slurry, into fine powder of 300-350 meshes powder and again crushing with sodium hexametaphosphate to obtain foliar fertilizer.    USE - For prolonging method of foliar fertilizer of chemical auxiliary agent to effective period (claimed).    ADVANTAGE - The method produces fertilizer auxiliary agent, through a physical modification and chemical modification of plant straw ash and so on natural nanometer material, increases the surface number, disperses performance and adsorption performance, where the leaf's surface, better absorbed fertilizer nutrient in the micro-nano structure auxiliary agent material. The foliar fertilizer improves the adhesive ability of the plant leaf surface, reduces the flying, volatilization loss occurred, so as to prolong the duration and improves nutrient utilization rate. The main raw material is natural and environment-friendly in nature, without secondary pollution, reduces the fertilizer dosage and time, saves labor and cost and reduces environment pollution.    DETAILED DESCRIPTION - Prolonging method of foliar fertilizer of chemical auxiliary agent to effective period involves: taking 200-400-mesh plant straw ash, fly ash, attapulgite and lignin according to 2-4:1-2:1-3:1-2 weight ratio, uniformly mixing to obtain composite material; adding the composite material to prepare into solution with the concentration of 50-200 g/l to obtain suspension in water, heating the suspension for 5-10 minutes; adding water into gamma-aminopropyl triethoxysilane by turbid liquid of the process at 50-60 degrees C, standing for 30-40 minutes at 150-200 revolution per minute (rpm) to stir for 20-30 minutes, removing the supernatant fluid, crushing rest slurry at 80-10 degrees C, crushing into fine powder of 300-350 meshes powder; crushing the obtained powder with 200-400 meshes sodium hexametaphosphate in a mass ratio of 85-90:5-10 mass ratio, to obtain foliar fertilizer which extend 3-8 wt.% chemical auxiliary agent efficiently.