ObjectiveTo summarize the application of spectral CT in the diagnosis of common, frequently occurring, and acute severe gastrointestinal diseases. MethodThe literature and guidelines on spectral CT were reviewed, and the main conclusions and opinions were summarized. ResultsThe spectral CT could obtain a variety of tissue parameters through a single scan. Through post-processing, multiple sequence images could be obtained, including virtual single-level images, virtual unenhanced images, iodine density images, effective atomic number images, etc. And multiple quantitative indicators could also be obtained, including iodine concentration, standardized iodine concentration, spectral curve, effective atomic number, etc. It could improve the signal-to-noise ratio of the image, reduce artifacts, increase iodine contrast, and decrease iodine load, then could improve the detection rate of active gastrointestinal bleeding and ischemic bowel diseases, improve the assessment accuracy of inflammatory activity of Crohn disease, and help to identify benign and malignant gastrointestinal tumors, determine the histological origin and evaluate the therapeutic effect. ConclusionFrom the conclusion summarized in this review, spectral CT images and quantitative indicators could provide more valuable information for detection, diagnosis, and prognosis of gastrointestinal diseases.