Gastrointestinal tumors (esophageal cancer, gastric cancer, colorectal cancer) seriously threaten human health, with a high incidence rate and cancer related hope mortality. Digestive endoscopy is the main method for screening gastrointestinal tumors. Early screening of gastrointestinal tumors can improve the detection of early cancer and improve prognosis. The five-year survival rate of early stage tumors after comprehensive treatment can reach 90%, while the five-year survival rate of late stage tumors is less than 30%. Therefore, the screening of gastrointestinal tumors is very important. Studies have shown that there are similarities in risk factors for gastrointestinal tumors, such as age, gender, family history, smoking, alcohol consumption, etc. Currently, established digestive malignancies are targeted at a single malignant tumor. At present, there is a lack of understanding of the overall risk factors associated with gastrointestinal tumors and the establishment of relevant risk prediction models. Therefore, we conducted a prospective, multicenter cross-sectional study to explore the independent risk factors of combined gastrointestinal tumors and establish a risk prediction model for combined screening of gastrointestinal tumors.