The invention relates to the technical field of databases, and provides a big data synchronization method and device based on Binlog, HBase and Hive. The method comprises the steps that: a Binlog filein a relational database is monitored, and real-time changing data is obtained; after a data synchronization device acquires the Binlog file data, the data synchronization device analyzes and acquires a database name, a table name, an operation type, a primary key and all field values; when the Binlog file data is stored in the HBase, the database name is correspondingly taken as a namespace of an HBase table, and the table is established; and the primary key is used as a rowkey of HBase data records, so that all changes of the database records can be found out through the rowkey, and data coverage updating can be performed. According to the method and device, no historical total data is reserved in a real-time table, the data size is small, and the real-time data query speed is high.