In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of Fe_3O_4@SiO_2@TiO_2@Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy dispersive X-ray(EDS), X-ray diffraction(XRD), UV–vis diffuse reflectance spectroscopy(DRS) and vibrating sample magnetometer(VSM) techniques. The photocatalytic activity of Fe_3O_4@SiO_2@TiO_2@Ho was investigated by degradation of methyl orange(MO) as cationic dye and rhodamine B(Rh B) as anionic dye in aqueous solution under UV/vis irradiation. The results indicate that about 92.1% of Rh B and78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results show that Fe_3O_4@SiO_2@TiO_2@Ho nanoparticles are better photocatalyst than Fe3O4@Si O2@TiO 2@Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles. In this work we synthesize a novel and highly efficient photocatalyst for degradation of methyl orange and rhodamine B. In addition, a new method for synthesis of Fe_3O_4 @ SiO_2 @ TiO_2 @ Ho magnetic core-shell nanoparticles with spherical morphology is proposed. The crystal structures , morphology and chemical properties of the as-assembled nanoparticles were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray The photocatalytic activity of Fe_3O_4 @ SiO_2 @ TiO_2 @ Ho was investigated by degradation of methyl orange (MO) as cationic dye and rhodamine B (UV-vis diffuse reflectance spectroscopy (DRS) and vibrating sample magnetometer (Rh B) as anionic dye in aqueous solution under UV / vis irradiation. These results that that about 92.1% of Rh B and 78.4% of MO were degraded after 120 and 150 min, respectively. These degradation results sho w that Fe_3O_4 @ SiO_2 @ TiO_2 @ Ho nanoparticles are better photocatalyst than Fe3O4 @ Si O2 @ TiO_2 @ Ho for degradation of MO and Rh B. As well as, the catalyst shows high recovery and stability even after several separation cycles.