雪崩光电二极管（APD）作为一种具有内部增益的光电探测器，被广泛地应用于光纤通信领域，其中平面型APD具有暗电流低、可靠性高等优点而被大量研究。但是平面型APD边缘处由于高电场易被提前击穿，影响器件性能。文章对抑制平面型APD边缘击穿的不同方法进行了综述，指出它们的结构差别，并重点介绍保护环法的原理及保护环各个参数的优化。

Avalanche photodiode, as a kind of photodetector with internal gain, is widely used in optical fiber communication, of which planar APD attracts great attention for the advantages of low dark current and high reliability. But planar APD may break down first at the edge for the high electric field, which will decrease the devices properties. In this article, different methods for preventing edge breakdown of planar APD were discussed and the differences are analyzed. The theory and parameter optimization of the method of guard ring is introduced with emphasis.