In order to obtain excellent slow light performance, we propose a photonic crystal waveguide (PCW) with extrinsic defect rods introduced into the center row of a complete square lattice rotated 45° counterclockwise and the second row adjacent to it. And successive cavities are introduced as electromagnetic energy reservoirs and light speed reducers for slow light transmission in the PCW concerning applications for optical communication, optical computation, and optical signal processing. Then, the plane wave expansion method is used to study the slow light transmission characteristics of the proposed structure, and the influence of the structure parameters on the slow light performance is analyzed. Finally, the bandwidth is obtained at 23.37 nm when the normalized delay bandwidth product (NDBP) reaches 0.40. The design method of the proposed structure provides an important theoretical basis for further improving the storage capacity with high bandwidth and high NDBP slow light.