Compared polyvinyl alcohol with citric acid as complexing agent, nanocrystalline nickel-zinc ferrite thin films were prepared by sol-gel method and dip-coating process under different temperature. The phase composition, morphology, magnetic properties and electromagnetic properties of nanocrystalline nickel-zinc ferrite thin films were studied by X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM) and vector network analyzer. The results show polyvinyl alcohol is the proper complexing agent for the preparation of nanocrystalline nickel-zinc ferrite thin films, which is stacked with sheet crystals and average diameter of about 20nm. The maximum saturation magnetization, the remanence magnetization and the coercivity of prepared nickel-zinc ferrite thin films are 39.38 emu/g, 11.47emu/g and 182.82 Oe, respectively. Through studying the microwave-absorbing properties of thin films, the maximal absorption quantity is determined at 9.2 GHz.