<p>4-chlorophenol (4-CP) is a prevalent organic contaminant, posed an insufferable threat to the environment, so it is significant to develop an efficient and operation convenient method for 4-CP treatment. In this study, as a solid hydrogen peroxide, sodium percarbonate (SPC) was activated by solar light to degrade 4-CP. By the introduction of SPC, the degradation efficiency of 4-CP reached 100% within 1.0 h, and the fitted rate constant was 0.0847 min⁻¹, which was 6.7 times of the solar light alone system (0.0126&#xa0;min⁻¹). Additionally, this study meticulously examined the effect of the initial concentration, pH value, and co-existed anions on 4-CP degradation. Reactive oxygen species (ROSs) trapping experiments indicated that both ·OH and CO₃·⁻ contributed to the degradation of 4-CP, but CO₃·⁻ was the predominant ROSs. With the addition of SPC, the formation of ROSs was enhanced, therefore accelerating the degradation process. Moreover, the degradation pathway of 4-CP in the solar light/SPC system was elucidated using LC–MS, and the acute and chronic toxicity levels of the degradation products were assessed in fish, daphnia, and green algae. This research enhanced the understanding of organic contaminant removal in solar light/SPC system and offered an efficient approach for treating 4-CP contained organic pollution water.</p>