The Ag-bearing antibacterial stainless steel has attracted substantial attention in the field of bacterial proliferation prevention. In this study, a Cu–Ag alloy was incorporated into a CD4MCu duplex stainless steel (DSS) to produce a good antibacterial property. The Ag-bearing CD4MCu duplex stainless steel samples were conducted solid solution treatment at various temperatures. The effects of the solid solution temperature on the microstructure, mechanical and corrosion properties, as well as silver ion release characteristics and antibacterial properties were investigated. Results show that apart from the original α, γ phases, Ag-bearing phases were formed in all samples after solid solution at different temperatures. The volume fraction of α and Ag-bearing phases decrease with increasing solution temperature. The tensile strength, hardness, elongation, and corrosion resistance first decrease and then increase along with the increase in the solid solution temperature. The heat treatment conducted at 1150 °C increases the strength, the hardness, the pitting corrosion resistance, and the antimicrobial capability simultaneously. The antibacterial rates of all the Ag-bearing CD4MCu duplex stainless steel samples after solid solution treatment are above 99%, indicating their good anti-bacterial capabilities.