In this work, the CoPtRu nanocomposite films with were fabricated on the Ru seed layer. The effects of Ru content on the microstructure and magnetic properties of the CoPtRu-SiO2 single layer nanocomposite films, and magnetic properties of the CoPtRu-SiO2/Co72Pt28-SiO2 double layer nanocomposite films were studied. Results showed that with an increase of Ru content in the CoPtRu film, the ordering degree of hcp-CoPtRu decreased, the volume of soft magnetic fcc phase increased, both the anisotropy constant and the saturation magnetization of the CoPtRu film decreased greatly. As a result, the anisotropy field of the film did not decrease notably. Therefore, the coercivity of the CoPtRu-SiO2/Co72Pt28-SiO2 double layer film was very close to that of Co72Pt28-SiO2 single layer film at both room temperature and low temperature.