The invention discloses a virtual database system and a query method, and the system comprises a client layer which is used for submitting an SQL code to achieve a business demand, an access layer which receives and authenticates the SQL code, a distributed service layer which analyzes the SQL code, a storage layer calculation layer which executes an SQL code request, and a meta-database which isused for storing actual physical data. The client layer is connected with the access layer, the access layer is connected with the distributed service layer, and the distributed service layer is connected with the reservoir calculation layer and the meta-database. According to the invention, the bottom layer use of the physical database is shielded, the heterogeneous cross-database query and mixedcalculation can be carried out as long as the unified SQL is written, developers can concentrate on the business logic development, and various bottom layer use methods of the database do not need tobe concerned.