The critical current density J_c is a key parameter for superconducting applications; meanwhile, in unconventional superconductors such as cuprates and iron-based systems, it can also reflect the characteristics of the underlying electronic phase diagram. Previous studies have reported sharp peaks in J_c at specific carrier concentrations, which have been discussed in connection with quantum criticality and the associated evolution of superconducting parameters. In this study, we systematically investigate the doping dependence of J_c in Bi₂Sr₂CaCu₂O_8+d (Bi2212) single crystals. We find that J_c exhibits two distinct peaks located in the underdoped and overdoped regions. Analyses of the magnetic field and temperature dependences of J_c reveal that this unusual behavior originates from the strong pinning mechanism. We also find that the strong pinning contribution is significantly enhanced by reduction annealing, suggesting that oxygen deficiency plays a crucial role in the enhancement of J_c. These results indicate that post-annealing treatments, which are commonly regarded as a means to control carrier concentration, simultaneously introduce substantial disorder that affects the electronic states and inhomogeneity. Our findings suggest that the interpretation of the electronic phase diagram of Bi2212 based solely on carrier concentration should be revisited, taking into account the influence of disorder.