In this research, photocatalytic removal of acid blue‌7 dye (AB7) as a model of high consumption dyes was studied by synthesized ZnFe2O4 nanoparticles and modified ZnFe2O4 with La3+ and Cr3+. ZnFe2O4, ZnFe1.8La0.2O4 and ZnFe1.8Cr0.2O4 nanoparticles were‌‌ synthesized by auto combustion sol-gel method and calcined at different temperatures. The synthesized nanoparticles were characterized by XRD and FE-SEM techniques. The XRD pattern of prepared nanoparticles showed that ZnFe2O4 nanocrystals were formed in the cubic structure and the mean crystallite size was about 25 nm, and the FE-SEM image showed that prepared photocatalyst was in nanoscale with low aggregation and porous structure. The photocatalytic removal of the AB7 dye was studied by synthesized nanoparticles, which resulted in the effective removal of the AB7 by photocatalytic process, and the individual effect of light and catalyst was insignificant in the process of elimination. Also, the effects of modification of catalyst structure by La3+ and Cr3+ on the removal efficiency were investigated, which showed that the significant effect of lanthanum. Finally, the effects of calcination temperature on the photocatalytic removal process of synthesized and modified ZnFe2O4 nanoparticles were investigated. The results showed that the maximum removal efficiency was observed in calcination temperature of 500°C. The lanthanum-modified Zinc ferrite spinel photocatalyst showed the highest removal efficiency about 64% at 60 minutes of irradiation time and calcination temperature of 500°C.