A device for compressing vertex data in three-dimensional (3D) image data includes a codebook design module and a codeword search module. The codebook design module is configured for: grouping residual vectors of vertices in 3D image data for codebook design; generating, for each group of residual vectors, a sub-codebook formed by a specified number of codewords; and sending the generated sub-codebook corresponding to a group of residual vectors to the codeword search module. The codeword search module is configured for: receiving a sub-codebook sent by the codebook design module; searching for a codeword of optimal match of a to-be-compressed residual vector of a vertex in 3D image data to be compressed; and taking an index of the codeword of optimal match and an index of a sub-codebook where the codeword of optimal match is located as compressed data of the vertex. A method for compressing vertex data in 3D image data is further disclosed. With the disclosure, it is possible to save codeword storage space, enhance encoding quality, improve a compression ratio of vertex data, and increase a compression efficiency.