The semantic annotation method of Buddhist terminology is an important issue in Buddhist research. Taking the early Buddhist terminology as an example, this paper summarizes the three basic methods of semantic annotation of terminology and their respective limitations, as well as the application and judgment of semantic annotation. There are three basic methods of semantic annotation: citation method, etymology method and context method, and their applicable conditions are different. In order to annotate semantics comprehensively and carefully, three methods are sometimes used comprehensively; sometimes it is necessary to analyze the semantics to explain the sememes and the relationships between them. The application of semantic annotation method is related to the general process of semantic annotation and has a certain order. Generally speaking, it is used in the following order: quotation - etymology - context - comprehensive analysis. There are three criteria for semantic annotation of terminology: context, semantics and practice. Only if these criteria are met, the semantic annotation of terminology is correct. The academic contributions of this paper are as follows: it summarizes the basic methods of semantic annotation of early Buddhist terminology, explaining the use process of semantic annotation methods, and puts forward three standards to test semantic annotation.