By introducing diffractive surface,with the particular negative dispersive and the power of realizing random-phase modulation,in optical system,a hybrid diffractive-refractive optical system of see-through head-mounted display for augmented reality with 26 mm eye relief,12 mm exit pupil and 20°(H)×15.4°(V) field-of-view is designed. The utilization ratios of energy of real world and virtual world are 1/4 and 1/2,respectively. The resolution of display,determined by the system resolution power,is 800×600 and the pixel size is 33 μm. The diameter of this system is less than 46 mm, and it applies the binocular. This head-mounted display not only satisfies the demands of user;s factors in structure, but also with high resolution, very small chromatic aberration and distortion, and the system satisfied the need of augmented reality.