The invention discloses a method for removing metal artifacts in CT images. The method comprises following steps: detecting effective energy of mixed energy X-rays, and acquiring a CT image containing metal artifacts, wherein the CT image is the mono-energy CT image under effective energy; reading a CT value of the CT image, converting the CT value into a linear attenuation coefficient under target mono-energy, then calculating the CT value under the target mono-energy, and acquiring a CT image under the mono-energy; performing subtraction on the mono-energy CT image under the effective energy and the CT image under the target mono-energy, and respectively retaining a metal part and a soft tissue part so as to obtain a subtraction metal image and a subtraction soft tissue image; replacing the CT value of the artifact part in the mono-energy CT image under the effective energy through related calculation so as to obtain a CT image whose artifacts are removed; and replacing the CT value of the black artifact part in the CT image whose artifacts are removed through related calculation so as to obtain a CT image containing a filling value. By establishing reasonable, effective, simple and rapid math models in the method, the metal artifacts in the CT images under mixed energy can be removed.