A distributed file system and a data block consistency managing method thereof are disclosed. The method comprises: a file location register generates the values of the counters corresponding to CHUNKs and the values of the counters are simultaneously stored in file access servers and a file location register; when writing data into a CHUNK, a file access client writes data into both the main and standby file access servers and revises the values of counters of CHUNKs in the file access servers into which data is written normally; the file location register takes the CHUNK whose counter has the maximal value as the normal and valid one according to the corresponding values of the counters of corresponding CHUNK reported by the main and standby file access servers.