The invention discloses a text plagiarism detection method and system. According to the method, the number and the length of extracted sentence fingerprints are reduced by deleting short sentences andadopting a truncated character fingerprint mode; the sentence fingerprints are extracted by deleting names, place names, organization names, time and other redundant information in the sentences, accurate detection of slightly-changed plagiarism contents is achieved, for example, the situation that the names, the place names, the organization names and other contents are changed can also be detected, and robustness is enhanced. Compared with a traditional text plagiarism method, the technical scheme provided by the invention greatly reduces the computation burden, improves the detection speed, is more suitable for quickly retrieving the same or similar place of the to-be-detected file and the original text with the copyright in mass (billion level) original texts, and outputs all the plagiarism texts and the corresponding plagiarism degree of the to-be-detected file.