为解决传统靶场光测成像设备人工调焦效率低，受人为因素影响大，难以保证得到全程清晰目标图像的问题，提出了一种粗调与精调相结合的快速搜索调焦算法。该算法借助对图像清晰度评价来自动搜索到正焦面。使用计算速度较快的Brenner函数以大步长进行粗略调焦，然后使用对清晰度变化较敏感的Tenengrad函数实现小范围，小步距的精确调焦。使用Mean Shift跟踪算法，实验中搭建了硬件系统平台。通过对同一待测目标在相同位置的多次调焦实验，结果表明，该自动调焦算法具有较好的稳定性，能够满足实际靶场测量准确度与实时性的要求。

In order to solve the problem of poor precision in observed target, measured by manual focusing in traditional shooting range optical measurement imaging device with low efficiency and indeterminacy, an algorithm of rapid auto-focusing combining roughly focusing and fine focusing is proposed. This method can automatically search the focal plane by evaluating the image definition. First, the Brenner function with high performance is used to roughly fousing. Tenengrad function with high sensitivity to the change of image definition is used to fine fousing in narrow range later. An algorithm for tracking based on mean shift is applied and hardware platform is set up in experiment. By the focusing experiments repeatedly to the same measuring target in the same place, the results of field test indicate that this method with high stability can satisfy the accuracy and velocity in actual measurement.