Photonic signals can be multiplexed independently in the space, time and wavelength domains. In this paper a new method using connection logical maps to describe the alteration of network structure from the space division switching network to the photonic switching network in three divisions is proposed for the first time. As an example, a multistage photonic switching network with 8 input ports and 8 output ports in the space only division, which matches Benes structure, is converted to another network in three divisions with the asme connection structure by this method.