Abstract: The invention relates to a bacterial antigen library of Brucella suis surface antigens, its preparation and use. The library comprises 205 surface protein genes of Brucella suis constructed in an expression vector. The library can be used to prepare recombinant Brucella surface antigens. The expressed proteins derived from the gene library are important for the development of new vaccines to prevent brucellosis, or diagnostic kits to detect Brucellosis. The proteins prepared from the gene library can also be used to prepare a protein array to investigate pathogenic mechanism of brucellosis.