The invention discloses a network-oriented multichannel big data acquisition system and method. The network-oriented multichannel big data acquisition system comprises a distributed oriented acquisition system framework composed of a forum data acquisition unit, a blog data acquisition unit, a news data acquisition unit and a data acquisition unit in a relational database, wherein the forum data acquisition unit is used for acquiring network data in an online forum and an offline forum with a dynamic webpage acquisition method and a webpage information extraction method respectively; the blog data acquisition unit is used for widely traversing blog sites to acquire blog Feed addresses, acquiring a blog corresponding to each Feed address in real time and tracking updated blog articles to acquire blog information in an incremental updating manner; the news data acquisition unit is used for extracting main body texts in a news webpage on the basis of a row block distribution function method; the data acquisition unit in the relational database is used for acquiring data in the relational database in batches with a data migration tool.