CT contrast agent based on Iodinated oil nanoemulsion is provided by Suzhou Beike Nanotech Co., Ltd. It is a milky transparent liquid, dispersed in pure water, and has been filtered and sterilized by a 0.22-micron filter membrane. It is adjustable in a certain range of size and iodine concentration, has good CT contrast enhancement effect, low nephrotoxicity, safety, environmental protection and no pollution, and has good dispersion and stability. It can be used for CT imaging of mouse liver and spleen, tumors, etc.