Data consistency processing method, device and system

The invention relates to a data consistency processing method, which comprises the following steps: receiving a first write request sent from a terminal, obtaining a global-increasing first request serial number corresponding to the first write request, and storing the first write request and the first request serial number into a request serial number queue in an association way; broadcasting the first request serial number and the corresponding first write request to proxy servers to cause the proxy servers to continuously write data according to a local request serial number and the first request serial number so as to cause the request serial number of the write request corresponding to the written data to be continuous, and returning a maximum request serial number when the data succeeds in being written; and associating the returned maximum request serial number with the proxy servers, and judging that the data succeeds in being written when any one proxy server returns the maximum request serial number