对自锁模掺钛宝石激光器的原理作了较详细的描述，指出克尔透镜效应是形成自锁模的主要原因。在自聚焦理论基础上，从无象散近似出发．推导出钛宝石棒的非线性矩阵，由此得出钛宝石激光器的谐振腔设计方法，并且讨论了谐振腔稳定性对自锁模的影响、软光阑与硬光间的不同之处以及腔内的群速度色散补偿。最后，将计算结果与实验作了比较．两者符合得很好。 The principle of self-mode-locked Ti: sapphire laser is described in detail. It is pointed out that the Kerr lens effect is the main reason for the formation of self-locking mode. On the basis of self-focusing theory, starting from the astigmatic approximation. The nonlinear matrix of titanium sapphire rod is deduced, and the design method of the resonator for Ti: sapphire laser is deduced. The influence of resonator stability on self-mode-locking, the difference between soft diaphragm and hard light, Within the group velocity dispersion compensation. Finally, the calculation results are compared with the experiment. The two fit well.