A document processing method and system are provided. A client divides at least one document into a plurality of document pages, and individually encrypts the document pages by a first key to obtain a plurality of encrypted pages. The client removes a part of words from the document pages to obtain a plurality of significant words, and individually encrypts the significant words by a second key different to the first key to obtain a plurality of encrypted significant words. The client records the encrypted significant words and a plurality of first index information in a significant word set (SWS), where the first index information indicates a page in the encrypted pages where the encrypted significant word comes from. Then, the client transmits the encrypted pages and the SWS to a remote server for storage.