Magnetic core-shell structure (1-x)Ni0.5Zn0.5Fe2O4/xSiO2 (x = 0-0.2) nanopowders were successfully prepared via the methanol combustion process, the as-prepared magnetic core-shell structure nanopowders were characterized by XRD, SEM, TEM, HRTEM, BET, and VSM techniques, and the adsorption performance of DNA onto them was investigated. The results showed that the magnetic core-shell structure 0.9Ni0.5Zn0.5Fe2O4/0.1SiO2 nanopowders exhibited a good adsorption capacity of DNA, and the adsorbance of DNA for magnetic core-shell structure 0.9Ni0.5Zn0.5Fe2O4/0.1SiO2 nanopowders was enhanced to 2.8 times for Ni0.5Zn0.5Fe2O4 nanoparticles. The adsorption kinetics of DNA in aqueous solution onto the magnetic core-shell structure 0.9Ni0.5Zn0.5Fe2O4/0.1SiO2 nanopowders at room temperature were investigated, and the kinetics data were in good agreement with the pseudo-first-order kinetic model in the initial DNA concentration of 50 μg/mL.