Self-activated long afterglow photocatalysts show great potential for all-weather wastewater treatment, with sustained photocatalytic activity even under dark conditions. However, the radiative combination of afterglow luminescence and photocatalytic degradation reaction has competitive utilization for photogenerated carriers, reducing afterglow duration and generating excessive hole accumulation, which significantly limits the efficiency of long afterglow driven photocatalytic degradation. Here, a long afterglow photocatalyst LiYGeO₄: Bi³ based on oxygen vacancy (V_O) was prepared, which released ultraviolet afterglow after activation by ultraviolet light irradiation and degraded organic pollutants via photocatalytic degradation driven by its own afterglow in dark condition. The trap concentration was improved by engineering oxygen vacancies and crystal fields, significantly enhancing the afterglow duration and intensity of V_O-LiYScGeO₄: Bi³⁺. A Fenton reaction system was constructed to further increase the concentration of active species, which maximized the photocatalytic degradation efficiency of V_O-LiYScGeO₄: Bi³⁺ during the afterglow duration. After 10 min UV irradiation to activate V_O-LiYScGeO₄: Bi³⁺ continuously released ultraviolet afterglow for photocatalytic degradation of Rhodamine B (RhB), reaching a degradation efficiency of 63% within 1 h in Fenton environment, which increased by 3.5 folds when compared to that of LiYScGeO₄: Bi³⁺ in the initial environment. This work provides a new approach for the design of afterglow photocatalysts and their application in wastewater treatment.