The invention discloses a recombinant protein A efficiently combined with IgG (Immunoglobulin G) and a construction method of an engineering bacterium thereof. The method comprises the following steps of: designing a recombinant protein A primer for IgG antibody combining areas E, D, A, B, C of a staphylococcal protein A (SPA) according to a gene sequence announced by the NCBI (National Center For Biotechnology Information), and adding a cysteine codon into an end C primer; amplifying by taking the genome of a staphylococcus aureus as a template to obtain a gene (SPA) of an encoding recombinant protein A antibody combining area, connecting the gene (SPA) with a plasmid pMD18-T, transforming competent E.coil JM109 to obtain a large quantity of recombinant plasmids pMD18-T-spa, storing the gene and increasing the copy numbers of the gene; and extracting the recombinant plasmids, performing double digestion on the recombinant plasmids and a plasmid pET-28a by using Noc I and BamH I, connecting a recombinant plasmid pET-28a-spa, transforming competent E.coil BL21, adding IPTG (Isopropyl beta-D-Thiogalactoside) of which the finial concentration is 1mmol/L for inducing expression at the temperature 30 DEG C, and identifying whether the expression is successful by using SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electropheresis).