Oblique Ring-Shape-Hole Photonic Crystal Waveguides (ORSHPCW) is a popular structure in designing optical buffers attracted many attentions recently. There are some parameters such as the radiuses of holes and pillars in the first two rows adjacent to defect that have significant effects on slow light properties. Consequently, one of the promising methods for effectively slowing the light speed down and controlling dispersion is to optimize these parameters, which is the motivation of this study. Particle Swarm Optimization (PSO) algorithm is one of the best proposed heuristic optimization algorithms in Artificial Intelligence applied to many engineering problem. In this work, this algorithm is employed to find the best values of the aforementioned radiuses for maximizing Normalized Delay-Bandwidth Product (NDBP) of ORSHPCW structure as the first systematic optimizer. Calculation results show that there is 30% improvement compared to the previous works, which is considered as a substantial achievement in this field.