Herein, we report a one-pot route to the formation of free-standing, large-area CNTs/TiO2 nanofiber membrane with enhanced photocatalytic activity. Through the hydrothermal reaction of the mixtures of CNTs, tetra-n-butyl titanate, and concentrated NaOH solution, the binary CNTs/titanate nanofiber membrane was readily formed. Through the post-treatment of acid washing and thermal annealing, titanate nanofibers within the membrane can be transformed into TiO2 nanofibers which are known to have a better photocatalytic activity. The photocatalytic studies show that the introduction of CNTs into TiO2 nanofiber membranes facilitated the separation of the photo-generated charges, leading to an enhancement of the photocatalytic activity toward the decomposing Methylene blue (MB) in water.