The invention discloses a binary disinfectant. The binary disinfectant comprises a liquid A and a liquid B, wherein the liquid A comprises acetic acid having the mass concentration of 95-98% and sulfuric acid having the mass concentration of 95-98%, while the liquid B is hydrogen peroxide having the mass concentration of 27.5-35%. The invention also discloses a preparation method of the binary disinfectant. The binary disinfectant is characterized in that glacial acetic acid and hydrogen peroxide taken as the major raw materials and prepared into the binary packaged disinfectant so that the sterilization effect and the stability of the disinfectant can be enhanced and then the disinfectant is capable of killing hepatitis A and B viruses, persistent viruses, influenza viruses and bacterial spores, and also capable of killing salmonella typhi, vibrio cholera, diarrhea and escherichia coli. The binary disinfectant can be used as the major disinfectant for controlling various viruses and the hospital cross infection, and can be applied to the disinfection and sterilization of viral pollutants, indoor and outdoor environments, hospital wards, common bathing pools, kindergartens, public places, breeding industry, hog houses, food processing industry, sewage treatment and the like.