对半导体抽运的Yb∶YAG克尔透镜锁模激光器进行理论分析计算，分析五镜谐振腔和四镜谐振腔的稳区不同，利用稳区范围变化对五镜谐振腔稳定锁模机理做出合理解释．详细计算分析Yb∶YAG激光器内克尔调制效应对锁模的影响，获得最佳腔参量．在腔内没有插入硬光阑的情况下，利用五镜腔实现了Yb∶YAG晶体克尔透镜锁模运转．理论分析和实验结果相符．

The five mirror cavity of diode pumped Yb ∶YAG Kerr-lens mode-locked laser was analyzed theoretically in this paper. To get stable self-mode-locking in the experiment,the best parameters of the cavity had to be found. Compared the five mirror cavity with the four mirror cavity,it was found that the mode-locking was much more stable in the five mirror cavity. The reasonable explanation of five mirror cavity stable mode-locking was given in this paper by using stability region theory. And the Kerr-strength of the five-mirror cavity was calculated. It would provide a theoretical method for the modulation of the diode pumped kerr-lens mode-locked laser.