The invention discloses a relational query method implemented on a large-scale data set and belongs to the field of semantic webs. The method comprises the following steps: 1) calculating connective subgraphs (only containing a same type of tags) in a semantic data directed graph G; 2) merging the connective subgraphs, and dividing the directed graph G into a plurality of subgraphs; 3) calculating a strongest connective subgraph C in each subgraph subjected to merging, and calculating a bipartite graph of the strongest connective subgraph C; 4) storing the shortest path of all the subgraphs Cinto a path set RS; 5) recording the tags (containing two points of a non-redundant tag path) in each divided subgraph so as to obtain a tag set of each subgraph; and 6) judging whether paths conforming to the query conditions exist in the directed graph G by using the tag set, if so, returning path query results, otherwise, carrying out traversal among the subgraphs, determining subgraphs which can reach a target node according to the path set RS, and then, returning the path query results by using the tag set of the subgraph. The method disclosed by the invention is used for supporting the relational query of mass data, and is strong in expandability.