Polyaniline (PANI)/MIL‐88A(Fe) (Px@M88) composites were constructed through a simple one‐pot hydrothermal method. The photocatalytic and photo‐Fenton activities of Px@M88 composites toward reduction of Cr(VI) and degradation organic pollutants were explored by white light irradiation. PANI, as a conductive polymer, can improve MIL‐88A(Fe)’s conductivity and the efficiency of photogenerated e−–h+ pair separation. In the presence of H2O2, a photo‐Fenton reaction occured to boost the degradation efficiency of organic pollutants like bisphenol A. In addition, P9@M88 showed excellent recycling and stability in cycling experiments. Finally, a possible reaction mechanism for photocatalytic degradation was proposed and verified by X‐ray photoelectron spectroscopy and electron spin resonance determination and electrochemical characterizations. PANI/MIL‐88A(Fe) composites exhibit outstanding photocatalytic activities for environmental remediation. In addition, the possible reaction mechanism is proposed and verified.