Hierarchical titanium dioxide (TiO2) nanofibers with distinctive microstructures were fabricated successfully via microemulsion electrospinning (ME-ES) followed by pyrolysis. The chemical composition, morphology and microstructure of hierarchical TiO2 nanofibers were characterized by Fourier transfer infrared (FT-IR), Energy dispersive X-ray (EDX) spectroscopy, Field emission-scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM), respectively. The photocatalytic performances were evaluated by decomposing methylene blue (MB) aqueous solution with UV light embedded with 365 nm light filter as the light sources. The results indicated that multi-channel, hollow, irregular hollow and mesoporous TiO2 nanofibers with mixed crystalline were obtained only by adjusting the ratio of tetrabutyl titanate (TBT)/paraffin oil in the micro emulsion system. In addition, the pores in the TiO2 nanofibers were axial-aligned for both the multi-channel and hollow nanofibers. All the TiO2 nanofibers prepared by microemulsion electrospinning displayed improved photocatalytic performances compared with the solid TiO2 nanofibers. The results has proved that micro emulsion electrospinning is indeed a simple and convenient method for fabricating hierarchical TiO2 nanofibers with improved photocatalytic performances.