The invention discloses a relational database-based big data platform unloading method and system. The method comprises the following steps of: extracting to-be-unloaded data from a relational database file, and converting the to-be-unloaded data into a file in a format appointed by a big data platform; if the relational database and the big data platform are located in same network environment, storing the file in the appointed format into an obtained distributed file system path; and otherwise, storing the file in the appointed format into the obtained distributed file system path through anintermediate medium. According to the method and system, data is simply and rapidly analyzed into big data platforms from database data sources, so that when being compared with traditional ETL tools, the method and system have the advantages of solving the defect that ETL only can unload relational data sources and big data platforms in a same network, satisfying different network environment requirements and then improving the efficiency.