The invention provides a multilingual plug-in language package implementation method and system, and the method comprises the steps: building a language package file through employing Microsoft OfficeExcel, wherein the language package file comprises a default language and a user language; converting the language package file into a Unicode text, and carrying out storage or transmission operationon the language package file in a Unicode text format; in Microsoft Office Excel, using cells in the same column and adjacent rows for folding and displaying user language entries, and ensuring thatthe width of the user language entries is not larger than that of corresponding default language entries by folding the user language entries; and opening the language package file in a text form in an application program, reading all corresponding entry contents of the language package file, performing assignment setting on the read entry contents, and storing the entry contents in a memory. Themethod can effectively solve the technical problems of an existing Excel language package, and has the advantages of being high in compatibility, complete in language display and rapid in interface language switching.