We theoretically present the model of six-port circulator with a ring of magneto-optical rods symmetrically coupled to the waveguides in a two-dimensional triangle-lattice photonic crystal. Coupled mode theory is used to predict the broadband condition. It is shown that the rod–waveguide coupling should be equal to the rod–rod coupling in the structure, in order to obtain excellent performance of device in a relatively large bandwidth. According to the analytical results, the circulator is optimized and its properties are investigated. The results show that the insertion loss of the circulator can reach to 0.017 dB and isolations for the isolated ports are all above 29 dB. The broadband, low insertion loss, high-isolation circulator with multiple ports presented here is compact in structure and appropriate for optical integrated systems and wavelength division multiplexing applications.