基于主光线传输方程，研究了鱼眼镜头前光组负弯月形透镜物像空间的视场角压缩比与结构参数之间的关系，并根据视场角压缩比及镜头尺寸的设计限制，初步确定前光组的结构参数。针对前光组具有平面对称光学系统的成像特性，应用平面对称光学系统像差理论计算前光组波像差；然后利用鱼眼镜头前、后光组波像差的平衡条件，求解后光组各透镜的光焦度及光学间隔；并将其作为限制条件，应用Zemax软件设计了由三块透镜组成的简单后光组系统。以该简单系统作为初始结构进一步复杂化，得到满足更大视场和孔径要求的鱼眼镜头。研究表明，所述方法为设计鱼眼镜头初始结构提供了一种新的思路，且避免了以往设计者过于依赖经验和参考专利的问题。

The transfer equation of the principal ray is used to study the relationship between the compression ratio of the field angle and the optical parameters of the pre-group optics of fisheye lens, and then the design parameters of the pre-group optics of fisheye lens are determined according to the requirement of compression ratio and lens dimension. Since the pre-group optics has the imaging performance of a plane-symmetric optical system, the aberration theory of plane-symmetric optical systems is applied to calculate its wave aberration. The focal power of every component and the gap between them can be solved from the wave aberration balance equations of pre- and back-group optics of fisheye lens. The solution is used as constraints, and Zemax is used to obtain a simple initial design of back-group optics consisting of three lenses. The lens complication and optimization is then performed according to the simple system. A fisheye lens is obtained, which satisfies the reguirement of bigger field of view and aperture. The study shows that the method discussed in the paper provides an approach to determine the initial structure design of fisheye lens and enables the designers not to rely heavily on experience and patents.