The invention discloses an efficient microbial agent for resisting insects, preventing diseases, increasing fertility and promoting growth. In order to solve the technical problem that the existing microbial agent does not have ideal effects of resisting insects, preventing diseases, increasing the fertility and promoting the growth. The technical scheme adopted by the invention is as follows: the microbial agent is obtained by implanting soybean protein, amino acid, fulvic acid and a medium trace element which are used as carriers into a mixture of ferment bacteria, endogenous bacillus and beauveria bassiana and fermenting for 48 to 60 hours at the temperature of between 38 and 46 DEG C; and diseases and insects are prevented and controlled through antibiotics and chitinase generated in the bacteria fermentation process according to the technical principle. The microbial agent has the technical effects that the soil can be improved, and the root system is stimulated to grow, so that crops well absorb required nutrients; the microbial agent has a good effect of resisting the infringement of root-knot nematode and stem eelworms, has quite positive promoting effects of swelling fruits and increasing the sweetness, has obvious promoting effects on crop growth, plant reinforcement, yellowing resistance, lodging resistance and rotting resistance, and integrates insect resistance, disease prevention, fertility increase and growth promotion; and the labor intensity is reduced, manpower and material resources are saved, and the production cost is reduced.