Photolithography of a pattern-forming process was developed with ultraviolet (UV) exposure and lithography methods, using poly(vinyl butyral) (PVB) with a nano-TiO2 composite as a photoresist. The PVB/TiO2 photoresist with high mechanical strength can be photodegraded because of the photocatalytic reaction during UV irradiation. After the PVB was removed from the exposed region, the TiO2 particles left after the photoreaction were easily removed by solvent, because of the low mechanical strength in this region. Results show that a pattern was able to be formed on substrates using this photolithography technique. The surface morphology of the PVB/TiO2 films associated with different exposure times was demonstrated. The dynamic intensities of functional groups for the residues (solid phase) and the volatile products (gas phase) during PVB/TiO2 photodegradation were analyzed. In addition, design of a photoreactor to shorten the UV-exposure time and improve the quality of the pattern-forming requirement was discussed.