The g‐titania functional additives were prepared via thiol‐ene click chemical reaction, and then the polylactic acid/g‐titania nanofiber membrane was prepared via electrospinning technology. Characterization via scanning electron microscopy and nitrogen adsorption/desorption showed that the average fiber diameter of the TP4 fiber membrane was 489 nm, the specific surface area was 34.69 m2·g−1, and the average pore size was 22.31 nm. The adsorption mechanism, photocatalytic degradation performance, and reusability of polylactic acid/g‐titania nanofibrous membranes were characterized. The results showed that the adsorption of methylene blue by TP4 nanofiber membrane followed a pseudo‐second‐order kinetic model, which could be represented by the Langmuir isotherm model, and the maximum adsorption capacity was 35.44 mg·g−1. In addition, the photocatalytic degradation of methylene blue by TP4 nanofiber membrane followed a first‐order kinetic model and exhibited high reusability. Therefore, polylactic acid/g‐titania nanofiber membrane, as an efficient dye removal material, shows a good application prospect in wastewater treatment.