The embodiment of the invention provides a codebook generation method, a data transmission method and a device thereof. The data transmission method comprises the following steps: receiving a label of a code word sent by UE in an antenna8 codebook; searching the code word identified by the label in the antenna8 codebook; and encoding data to be sent by use of the code word, and sending the encoded data, wherein, the antenna8 codebook at least comprises the code word rank8 of which is eight, which is the product of an inverse matrix of a rotation matrix of antenna8 and a 8-dimensional matrix formed by the code word rank4 of which is four; or the code word rank8 of which is eight is formed by expanding the code word rank8 of which is 4, and the code word rank8 of which is 4 is formed by an antenna4 code word. By adopting the technical proposal provided by the embodiment of the invention, the code word in the antenna8 codebook is applicable to various scenes such as dual-polarized strong correlation, dual-polarized weak correlation, single-polarized strong correlation, single-polarized weak correlation and the like.