In the present paper, a novel thermal plasma method is proposed to synthesize ZnO-Fe2O3 nanocomposite, with different percentages of iron, namely 3, 5, and 7%. This method is an efficient feasibility of the Zno-Fe2O3 nanocomposite synthesis. The nanocomposites are synthesized by homemade direct current (DC) plasma torch. They are analyzed by different methods. The bandgap is determined by diffuse reflectance spectroscopy (DRS). The photocatalytic performance of Zno-Fe2O3 is evaluated. The results show that the structure of nanoparticles is spherical, which is more favored in the industry. Also, the particle size distribution is uniform. The average size of nanoparticle crystals increases with increasing iron content. Despite the formation of nanocomposites, due to the lack of support for nanoparticles, the results of photodegradation are not satisfactory. Highlights Production of nanocomposites by thermal plasma technique Production of spherical and rod nanocomposites Investigation of photocatalytic properties of nanocomposites By including iron, the size of nanostructures is significantly reduced. By adding iron to zinc, the structure of nanoparticles changes from rod to spherical which is more favored in the industry