The invention provides a log analysis method and system based on a syntax tree and a computer readable medium, and relates to the technical field of log analysis, and the method comprises the steps: obtaining at least one to-be-analyzed original log; Matching the original log with a lexical analyzer to obtain a first matching result; If the first matching result is that matching fails, carrying out grammatical analysis on the original log, generating a syntax tree based on the grammatical analysis result, wherein the syntax tree comprises a plurality of nodes, and each node is used for representing one piece of field information in the original log or representing one piece of operator information in the original log; And traversing the syntax tree, and obtaining field information in eachnode in the syntax tree by utilizing a regular expression. According to the method provided by the invention, for each to-be-analyzed original log, the original logs with different structures are analyzed through the same regular expressions, so that the redundancy of regular expression contents is reduced, and the repeated labor process of rule writing personnel is reduced.