The optical response of oxygen-deficient La0.6Ca0.4MnO3-δ (LCMO) thin films was studied using continuous wave and pulsed lasers with wavelength of 532 nm. The influence of oxygen deficiency on the optical response of LCMO thin films in metallic and insulating state has been analyzed. At room temperature, oxygen-deficient LCMO thin films show obvious optical response with photo-conductivity improved by 36.4% and rise time of 30 ns when illuminated by a laser pulse of 7 ns duration at the light power of 750 mW. Since the laser photon energy is larger than the band gap of the thin films, electron-hole pairs are created in the film. For the electrons can be captured by the oxygen vacancy easily, then extra holes carriers are produced, which can induce local insulator-metal phase change and obvious optoelectronic effect. The results show potential application of oxygen-deficient LCMO thin films in optoelectronic devices.