Huge difference of surface energies between dielectric and metal provides an effective method to tune the structure and magnetic properties of films. Due to the difference of surface energies between SiO2 and Fe, dopant of SiO2 with 3.6% in atomic ratio in Fe film transforms the strip and column structure in the Fe films to equiaxed crystal formed by nanoparticles of the Fe-SiO2 films. Zeeman energy of applying high magnetic field (HMF) during film growth increases Fe atomic aggregation and atomic diffusion of SiO2 into the grain boundary. This leads to the improvement of the particle size with applying HMF during the film growth. These structural evolutions have a significant effect on the performance of the films. After the dopant of SiO2, the saturation magnetization M-s of the Fe-SiO2 film (324.6 kA/m) is 73.2% less than that of the Fe films. The coercivity H-c decreases 204.0% to 788.04 A/m. However, the Ms increases 44.3% and the H-c increases 27.4% for the Fe-SiO2 film with applying HMF during the film growth.