Abstract: This paper discusses the method of geometry optics (GO) and physics optics ( PO) to calculate the secondary electromagnetic scattering on the geminate cells. It establishes the secondary scattering theoretic model and calculates the secondary electromagnetic scattering of some typical bodies and complex targets by the quick ray trace arithmetic to search geminate cells. It is shown that the results oi this method are very close to the theoretic results. But the calculation by this method is very quick. It may improve the prediction speed and reliability in the visual prediction system of complex targets.