NOVELTY - Method for preparing biological pesticide, involves (a) taking Tripterygium plant crude extracts, dried tea pigment, dispersing agent, emulsifier, and solvent or filler, (b) preparing Tripterygium plant crude extracts by washing the roots of Tripterygium, drying and crushing the washed roots, adding 95% ethanol to the root powder, performing Soxhlet extraction and concentrating the extract, and (c) subjecting the obtained crude extract to indoor bioassay, screening suitable fillers or organic solvents and preparing the medicament.    USE - The method is useful for preparing biological pesticide (claimed).    ADVANTAGE - The method is rapid and environmentally-friendly, and prepares biological pesticide having high medicinal content.    DETAILED DESCRIPTION - Method for preparing biological pesticide, involves (a) taking 0.8-25 wt.% Tripterygium plant crude extracts, 1-10 wt.% dried tea pigment, 2-12 wt.% dispersing agent, 3-13 wt.% emulsifier, and 100 wt.% solvent or filler, where the dispersing agent is sodium lignin sulfonate, the emulsifier is sodium dodecylbenzenesulfonate, the solvent is organic solvent of xylene and the filler is diatomaceous earth, (b) preparing Tripterygium plant crude extracts by washing the roots of Tripterygium, drying and crushing the washed roots, adding 95% ethanol to the root powder in a volume ratio of 1 g:10 ml, performing Soxhlet extraction and concentrating the extract obtained from the above-mentioned method, and (c) subjecting the obtained crude extract to indoor bioassay, determining active ingredients and toxicity coefficient of more than 150, adding dispersants or emulsifiers to the obtained mixture, screening suitable dispersants and emulsifiers to the mixture, increasing the dispersion and field efficacy of the product, screening fillers or solvents depending on chemical nature of active ingredient, screening suitable fillers or organic solvents for processing products, and finally preparing the medicament in the form of emulsifiable concentrate by mixing the above-mentioned active ingredients in container containing solvent, completely dissolving the mixture, adding emulsifier, mixing, filtering and extracting the mixture and obtaining milk aliquots, or wettable powder by mixing the above-mentioned two ingredients in container, mixing filler, dispersing agent, stirring the mixture, crushing the mixture, and packaging the crushed mixture.