本文扼要叙述了第二代化学合成专家系统的设计思想。其中包括：从线型到连接表表示的转换算法，对分子结构、分子结构同构判别法及相似度计算；除向前推理方法外，还增加了向后推理的方法；用模式匹配的方法将类反应变换为预测反应；环结构的识别和子结构匹配算法等。这些技术对于合成专家系统都是至关重要的。 This article briefly describes the design idea of ​​the second-generation chemical synthesis expert system. Including: from the linear to the connection table representation of the conversion algorithm, molecular structure, molecular structure isomorphism discrimination and similarity calculation; in addition to forward reasoning methods, but also increased the method of backward reasoning; pattern matching method The class reaction is transformed into a predictive reaction; ring structure identification and substructure matching algorithm. These techniques are crucial to the synthesis of expert systems.