The invention discloses a net label input prompting device comprising a label input model, an asynchronous request module, a label prompting module, a label publishing display module, a label correcting module, a user historical label processing module, a topic keyword extracting module, a tabbing module and a label index storage module. The label input model, the asynchronous request module, the label prompting module, the label publishing display module and the label correcting module are arranged on a client of user terminal equipment. The user historical label processing module, the topic keyword extracting module and the tabbing module are arranged on a web server. The label index storage module is arranged on a cache server. The net label input prompting device has the advantages that during label inputting, the relative labels are automatically prompted for the user to select, to be specific, the relative labels include labels relative to the topic, labels fuzzy matched with input Chinese characters or Pinyin and previous input labels. In this way, friend auxiliary prompting function is achieved, inaccurate classification, caused by synonymous words, is avoided, and the wrong label is corrected.