Disclosed is an oil soluble pesticide nm capsule and preparation method, having weight ration of: pesticide: 0.5-4%; high molecular compound: 8-25%; mixed-surfactant: 8-20%; cosurfactant 3-10%; crosslinking agent 0.5-1.0%; organic solvent 3-10%; water: added to 100%, wherein the high molecular compound is selected from sodium lignosulfonates, chitosan, gum arabic or glutin, one or two is/are selected for agglutination reaction, forming capsule skin of the nm capsule; the capsule core is pesticide bulk drug, selected from diflubenzuron, emamectin benzoate, abamectin, imidacloprid, ivermectin or highly active cypermethrin. The mixed-surfactant adopts nonionic surfactant and anionic surfactant for compound. The pesticide nm controlled release preparation prepared by the invention is easy in storage, high in stability, large in drug-loading rate and high in dispersion.