The present invention provides a relay selection routing method based on direct communication of a terminal, applied to a base station, including: establishing a database of a topological structure of a direct communication terminal on a network side; when a change of the topological structure is detected, updating the database of the topological structure; when a direct communication service request is received, determining a data sending path and a destination relay node corresponding to the direct communication service request according to the database of the topological structure, sender information and receiver information of the direct communication service request and a preset selection principle; and establishing a direct communication data sharing network corresponding to the direct communication service request according to the data sending path and the destination relay node. Correspondingly, the present invention further provides a relay selection router based on direct communication of a terminal.