论述了双通道头盔显示器光学系统的结构特点。根据对双通道头盔显示器应用要求的讨论，确定了它的技术指标。分析了离轴像差的特性，并在光学系统合适的位置处使用合理的自由曲面面型，有效地校正了离轴像差。设计的离轴双通道头盔显示器光学系统的技术指标为视场40\O×30\O，出瞳直径15 mm，焦距26.4 mm，眼点距25 mm，波长540~560 nm，后截距大于3 mm，眼分辨率满足在0.88 lp/mrad空间频率处的调制传递函数（MTF）值大于0.1。该系统的结构紧凑（系统尺寸70 mm×122 mm），重心位置适当，可以内嵌入头盔侧面使用。

Structure characters of a dualchannel helmet mounted display （DCHMD） optical system was analyzed. Based on the discussion of the requirements of DCHMD in application, the system′s technical specifications were presented. The offaxis aberration was analyzed and corrected by proper freeform surface at the right place of the optical system. A DCHMD optical system was developed with technical specifications: 40\O×30\O field of view, 15mm exit pupil diameter, 26.4 mm effective focal length, 25 mm eye relief distance, wavelength range 540~560nm, back focal length more than 3 mm and modulation transfer function (MTF) higher than 0.1 at the frequency of 0.88 lp/mrad. This system has a compact size (70 mm×122 mm) and a decent center of gravity, and could be embedded in the helmets.