Porous fibers are capable of large amounts of oil adsorption, owing to their extremely large surface area. The novel aggregation-induced-emission (AIE)-active polymer was synthesized by anchoring AIE-active initiators to the end of polymer chains through atom transfer radical polymerization. The porous fibers based on the synthesized AIE-active PMMA were fabricated through the electrospinning technique. The obtained porous fiber shows exceptional fluorescence; green fluorescence in the porous fiber can be switched off and on by the adsorption and desorption of silicon or bean oil. The fluorescence quenching phenomenon is due to the aggregation state change of the AIE molecules accompanying polymer swelling during the cyclic oil adsorption. Such fluoresent porous fibers can be used to improve the process of oil adsorption, which could have promising applications in the areas of self-cleaning materials, ultra-highly sensitive sensors and biomaterials.