Multi-walled carbon nanotubes (MWCNTs) are functionalized by hydrogen peroxide under UV, then they are used to prepare vanadium oxide-carbon nanotube composite films by Sol-Gel, and a new method is proposed to produce vanadium-oxide thermistor films. Compared with the single vanadium oxide films, the as-prepared composite films possess lower square resistance and optical band gap, larger temperature coefficient of resistance and light absorbance, and higher carrier migration rate. Therefore, such composite films are more suitable to be applied in uncooled infrared detectors.