The invention discloses a big government data preprocessing system which comprises a data extraction module, an unstructured data extraction module, a data preprocessing module, a distributed scheduling framework and a management console, wherein both the data extraction module and the unstructured data extraction module are connected with the distributed scheduling framework. According to the big government data preprocessing system, the problems of low efficiency, poor accuracy, load imbalance, poor concurrent working capability, incapability of intelligence and the like of an existing preprocessing system during big data preprocessing are solved. The invention further provides a big government data preprocessing method.