Data sharing method, device and system based on block chain

The invention provides a data sharing method, device and system based on a block chain. The method comprises the steps of obtaining shared data; establishing an ID corresponding to the shared data; extracting feature values from the shared data, and wherein the feature values are used for representing features of the shared data; generating uplink data according to the ID, the characteristic value and the shared data; and uploading the uplink data to the block chain, thereby enabling a user to determine matching information matched with the target shared data from at least one piece of target uplink notification information acquired by the service platform, and enabling the service platform to acquire the target shared data through the block chain according to the matching information, wherein the matching information comprises a target ID and a target feature value in the target uplink data stored in one block, and the target ID comprises a to-be-queried code input by a user and used for querying the target