The invention discloses a method for washing and sterilizing carcasses and/or meat pieces of livestock and poultry by utilizing ozone water. The method for washing and sterilizing carcasses and/or meat pieces of livestock and poultry or prolonging the quality guarantee period of carcasses and/or meat pieces of livestock and poultry comprises the following steps: spraying carcasses and/ or meat pieces of livestock and poultry with ozone water before treatment to obtain the treated meat pieces of livestock and poultry. The method disclosed by the invention can be used for washing and sterilizing carcasses and/or meat pieces of livestock and poultry, reducing microorganisms on the surfaces of carcasses and/or meat pieces of livestock and poultry and prolonging the quality guarantee period of carcasses and/or meat pieces of livestock and poultry.