At first, the development of compound eye bionics in China is briefly reviewed. The field of view, angular resolution and optical aperture of the compound eye optical system are defined. And then, the effective sight distance of the dragonfly compound eye is calculated by formula and experiment. The optical apertures of the dragonfly compound eye for point target, wide background outside the effective sight distance and cylindrical or strip target inside the effective sight distance are given. It is shown that the apposition multi aperture optical system of insect compound eye has the performance of orientation and tracking. At last, the applications in national economy and military are prospected.