Carboxymethyl cellulose (CMC)/bismuth ferrite (BiFeO3) nanocomposites with optical excitation of 490 nm were successfully prepared by impregnation method and were characterised by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM) and UV-Vis technique. The photocatalytic efficiency of the composite was further evaluated by degradation of methyl orange (MO) at wavelength 464 nm under direct sunlight irradiation. The incorporation of 0.8 w/w% BiFeO3 catalyst within the CMC film had shown a remarkable removal efficiency of 10 ppm MO by 91.62% as compared to pristine BiFeO3 with only 0.7% removal. There exists efficient synergistic effect of photodegradation and adsorption of MO onto CMC-BiFeO3. Kinetics studies revealed that the MO removal dominantly governed by adsorption that obeys pseudo-second order kinetic model. The photocatalytic activity has high effect in acidic condition. The recycling ability of unwashed nanocomposite confirming that the photocatalyst was essentially stable.