Various methods for analysing topological equivalence of multistage interconnection networks (MIN's) were reviewed briefly. Topological equivalence and its variety of free-sauce optical interconnection crossover networks with SW bsnyan (F=S=2) networks were studied by using the graph analysis method (GAM) for topological equivalence of MIN's. This will develop the POtential applications of optical crossover networks in systems of digital optical computing, photonic switching and parallel multiprocessing computers.