This article introduces the methods of antibacterial weight increment for silk fiber. Weight increment process was carried out under high temperature and pressure. Grafted liquid contained methyl acrylic acid ester derivative, initiator, nonionic or anionic surfactant and unglued waste water. In this way,the waste water was recycled, so these methods have the benefits of saving resource and reducing pollution, and are according with the requirement of recycling economy and cleaner production. Silk fiber will achieve ideal weight increment and antibacterial function after treatment.