In this study, the phosphorescence property of the activated CaAl 2 O 4 nanoparticles was used to improve the photocatalytic properties of WO 3 particles.. In this regard, initially CaOl 2 O 4 nanoparticles activated with Eu 2+ : Nd 3+ ions were synthesized by combustion method in a reducing atmosphere (90% Argon + 10% Hydrogen). Then, the ability of the composite photocatalyst WO 3 and CaAl 2 O 4 : Eu 2+ : Nd 3+ were studied in the degradation of methylene blue dye. To prevent the dispersion of the particles in the solution and prevent the loss of the nanocomposite components during the separation process, the WO 3 and CaAl 2 O 4 : Eu 2+ : Nd 3+ powders were mixed completely with ethylene terephthalate traarent resin (0.0125g CaAl 2 O 4 : Eu 2+ : Nd 3+ , 0.0750 g WO 3 and 0.5 ml ethylene terephthalate resin). Then, the mixture was stabilized on the glass surface by polymerization of ethylene terephthalate resin at room temperature using a Co 2+ catalyst. The resulting nanocomposite has a stable structure and is firmly fixed on the glass surface. Then, the photocatalytic ability of the obtained nanocomposite for removal of methylene blue from aqueous solution was investigated. For this purpose, the resulting nanocomposite in aqueous solution containing methylene blue exposed to light with a wavelength of 380 nm from seven LEDs with a total power of 7 Watts. Finally, the effects of parameters such as pH, composite composition ratio, source light intensity, oxidizing effect of H 2 O 2 and initial concentration of dye were investigated. The results showed that the highest removal percentage of methylene blue is obtained at pH = 10 and in the 1: 6 mass ratio of CaO 2 O 4 : WO 3 (0.0125:0.075 g). After optimization of the variables, the highest removal percentage of methylene blue (initial concentration of 7.5 mg. L -1 ) under emission lights of 7 LEDs was reached to be 97% during 3 h. In addition, the methylene blue (initial concentration of 7.5 mg. L -1 ) degradation process was performed under optimum conditions and using the direct sunlight (as light source). The results showed that the nanocomposite is able to remove 100% methylene blue dye during 30 min.