Abstarct: In recent years, mextal organic frxameworks have attracted a lot of attention in the field of photocatalysts due to their diverse properties and high porosity. Using visible light to perform photocatalytic reactions is also a promising way to clean the environment. In this research, the mextal organic frxamework MIL-88(Fe), which is a network of iron atoms and terephthalic acid organic lixnkers, is synthesized and encapsulated with magnetic "Co" 〖"Fe" 〗_"2" "O" _"4" nanoparticles by solvothermal method. The fabricated magnetic nanocomposite was used as a photocatalyst with the photofenton process in the degradation of cationic methylene blue dye. The physical and chemical structure of "Co" 〖"Fe" 〗_"2" "O" _"4" "@MIL-88(Fe)" was identified using various analyzes such as FT-IR, XRD, BET and FESEM. Factors affecting the rate of color degradation such as time, pH, amount of photocatalyst, initial concentration of color and concentration of hydrogen peroxide were investigated and the kinetics of degradation were investigated under optimal conditions. The rate of color degradation in the optimal state by photocatalyst was reported as 100%. The results show that" Co" 〖"Fe" 〗_"2" "O" _"4" "@MIL-88(Fe)" is a very efficient photocatalyst with the ability of easy magnetic separation from the wastewater solution and can be used in several steps to maintain its photocatalytic property after recovery.