<p>Crystal defect engineering, as a key strategy for regulating the performance of semiconductor photocatalysis, has received extensive attention. This study successfully constructed controllable crystal defects and oxygen vacancies in the Bi₂WO₆ lattice by regulating the doping amount of Zr element. Combined with the photocatalytic activation of PDS, this system achieved efficient co-degradation of rhodamine B (RhB). The degradation rate of RhB reached 99.12% after 8 min of light exposure, and its reaction rate constant (0.05242 min⁻¹) was 62.40 times that of pure Bi₂WO₆ under light conditions. The XPS and EPR results jointly confirmed that Zr can replace W⁶⁺ in the Bi₂WO₆ crystal structure and form defects, generating a large number of oxygen vacancies. Further characterization through photoluminescence spectroscopy (PL), photocurrent testing, and electrochemical impedance spectroscopy (EIS) revealed that Zr₃-Bi₂WO₆ has a higher charge migration rate and better carrier separation efficiency, which jointly promoted the improvement of photocatalytic performance. Through careful analysis of the experimental results, the crystal defects and oxygen vacancies mediated by Zr doping played a key role in regulating the photocatalytic performance of Bi₂WO₆, providing important references for the design of efficient solar-driven advanced oxidation systems.</p>