Abstract: This paper develops the method presented in reference (1) where the Fermion transformation is used to obtain the ground state of the Ising model. According to that after the Ferrnion transformation, the phase boundary can be obtain using the condition that energy of excited state is greater than zero, we propose that phase boundary can be obtain by directly comparing the energy of the vacuum state. Using this method, we study the most general spin S=1 Ising antifer-romagnetic model with nearest neighbor interaction, and obtain rigorously the ground state energy and the OK phase diagram of the model on fcc lattice. Meanwhile, using equation of many phase point, we divide the plane of parameter k,l into 56 regions, which correspond to topologi-cally distinct OK phase diagrams.