A type of two-dimensional photonic crystals with a quasi-honeycomb structure, which is formed by introducing two consistent dielectric cylinders into a triangular lattice, is investigated here. The relationship of its band gaps with the position of cylinders is numerically calculated and the photonic energy band is evaluated by the frequency domain method. The calculated results demonstrate the existence of large band gaps in quasi-honeycomb-structured two-dimensional photonic crystal. At a certain filling ratio, the largest absolute bandgap can be obtained by optimizing the position of the cylinders introduced.