Data sharing method and device based on block chain

The invention provides a data sharing method based on a block chain, and relates to the technical field of block chains. The data sharing method comprises the steps that a digital certificate is generated according to a current service, and the digital certificate comprises at least one declaration attribute; when the industry attributes of a plurality of transaction nodes involved in the xth business process are the same, the nth transaction node configures the access authority of the (n + 1) th transaction node to the declaration attribute in the digital certificate; when the industry attributes of at least two of the plurality of transaction nodes involved in the yth business process processing are different, newly adding a declaration attribute in the digital certificate by the mth transaction node; and the mth transaction node configures the access authority of the (m + 1) th transaction node to the newly added declaration attribute in the digital certificate. The invention further provides a data sharin