The invention discloses a social text-oriented cascade linear entity relationship extraction method, which adopts a cascade linear extraction mode, that is, the method firstly detects relationships contained in a given text, and then takes each relationship as additional knowledge to guide the subsequent extraction process of a head entity and a tail entity. According to the method, two decoders, namely a relation decoder and an entity decoder, are further designed, and the two decoders are jointly used for extracting the entity relation triad. By means of the method, the extraction accuracy of entity pairs (the head entity and the tail entity) and the performance of combined extraction can be improved, the overlapping problem can be naturally solved through a relation-first cascade extraction method, and then a more accurate premise can be provided for construction of the knowledge graph.