This paper aims to select TiO2 and SiO2 high and low refractive index materials, design and prepare 500~650 nm, 780~830 nm, 1 050~1 080 nm three-band compatible dielectric high reflective films. The spectral properties, stress characteristics and laser damage resistance of high reflective films composed entirely of dielectric materials for multi-band application are studied, and the large aperture film samples with good stress state are obtained. The process parameters of monolayer films were studied, with the monitoring wavelength 560 nm, based on the electric field intensity distribution, and film structure was optimized to be G/(HL)8H(2L)4 (1.4H1.4L)8H2L(1.9H1.9L)81.9 H/A. Low refractive index layers were added between different film stacks to suppress the nominal problem, and the reflectance spectral was smoothed, wide-band large-size multilayer high reflective film with good performance was successfully prepared on a large aperture substrate of ф220 mm by ion beam assisted electron beam evaporation technology. Its reflectance spectral was in the visible light range of 500~650 nm, with the average reflectivity of 99.5%, the peak reflectivity of 99.9%, the minimum reflectivity was 95.1%; within the scope of 780~830 nm, the peak reflectivity was 99.9%, and the average reflectivity was 99.8%, and the minimum reflectivity was 99.6%; in the 1 050~1 080 nm band, its average reflectivity could reach 99.8%, and the peak reflectivity reached 99.9%, and the minimum reflectivity reached 99.7%; reflectance spectral of large aperture film sample at different positions were high consistent. The laser-induced damage threshold of film was 7.1 J/cm2, and the residual stress was –293.59 MPa. The film thickness uniformity of large aperture film sample is good, and the film is compact without wrinkle, crack and falling off phenomena, with higher fastness and excellent laser protection performance.