First, it is best to consult with the CT room before the CT examination to see what preparations need to be made. During pregnancy, abdominal CT examination should be done with caution, and when doing other parts of the examination, certain protective measures should also be taken for the abdomen to avoid the impact of X-rays on the fetus. Third, no other imaging examinations should be done within one week before the abdominal examination, especially no barium gastrointestinal imaging, so as to avoid the formation of artifacts from the residual contrast agent in the intestine, which may affect the quality of CT images and lead to misdiagnosis. Before CT examination, abdominal fluoroscopy should be done to see if the contrast agent is exhausted. Fourth, before liver, biliary and pancreatic examinations, various laboratory tests, abdominal plain films and ultrasound should be done. Before kidney examination, pyelogram and ultrasound should be done. Sixth, before the examination of the chest, the chest X-ray should be taken. Before the spinal examination, the front and side of the spine, oblique photos, etc. should be taken first. Eight, the abdominal examination should be routinely oral negative or positive contrast agent to fill up the gastrointestinal tract, and negative contrast agent should be used when considering stones. The amount of contrast agent and the way of using it are different for different parts of the examination. When divided into different doses, the interval time is short for the upper abdomen and long for the lower abdomen.