Data slices present some properties of data cube. When data cube cannot be accessed for some reasons, it is very useful to reconstruct data cube based on data slices to discover the implicit information. Therefore, in order to reconstruct data cube, a practical method named Data Cover Method is presented, which creates the multidimensional fine-granularity space by the join operation between data slices, and splits the multidimensional space of data slice into multidimensional fine-granularity space by the basic operations of the DBMS (database managent system),and support the application enviromment of large data set efficiently.