Data communication method

The invention discloses a data communication method, which belongs to the technical field of data transmission, and comprises the following steps: an initialization step S10: generating an index of each data for a data block, and calculating the number M frames of data in each frame; s201, performing statistics on changed data in the data block in the sending period and the number m of the changed data; s202, extracting m pieces of change data, and storing the m pieces of change data in a cache 1 according to a form of m groups of indexes + data; s203, traversing the data blocks, and sequentially extracting M frames-m complementation data from the data blocks corresponding to the sending period according to the data which are not changed in the data blocks and are not sent before traversing; the data are stored in a cache 2 in a form of M frames-m groups of indexes + data; s204, merging the cache 1 and the cache 2 to obtain M frame group index + data, and packaging and sending a frame containing the correspon