The invention discloses a method generating IL instruction lists of PLC ladder diagrams, and relates to the technical field of compiling or interpretation methods of a high-level language. The method comprises the following steps of (1) conducting first-layer classification and classification treatment on the PLC ladder diagrams through a classification algorithm, (2) then conducting second-layer network-dividing treatment, after a process that the IL instruction list of each level of PLC ladder diagram is performed, conducting IL instruction list converting treatment on the level of the PLC ladder diagram through a sub PLC ladder diagram compiler algorithm according to the network sequence, (3) finally, conducting third-layer branch treatment, conducting traversal on pels of each line of the network, conducting IL instruction list conversion treatment, and generating the IL instruction lists. The method is used for generating the IL instruction lists, and the method has the advantages of being convenient to implement and fast, efficient and short in failure checking period, and having the high self-adaption performance.