Objective To explore the application value of abdominal ultrasound combined with CT in the preoperative staging of gastric cancer. Methods 88 cases of patients with gastric cancer treated in our hospital from January 2012 to October 2015 were selected as the research objects. All patients underwent abdominal ultrasound and multi-slice spiral CT examination before operation. The pathological results were taken as the standard to compared the accuracy rates of US, MSCT and US+MSCT in preoperative staging. Results The accuracy rates of US, MSCT and US combined with MSCT in T staging were 78.4% (69/88), 81.8% (72/88) and 92.0% (81/88), respectively. That of US combined with MSCT was higher than that of US alone and MSCT alone (P<0.05); The accuracy rates of US, MSCT and US combined with MSCT in N staging were 68.2% (60/88), 80.7% (71/88) and 94.3% (83/88), respectively. That of US combined with MSCT was higher than that of US alone and MSCT alone (P<0.05); The accuracy rates of US, MSCT and US combined with MSCT in M staging were 64.8% (57/88), 81.8% (72/88) and 93.2% (82/88), respectively. That of US combined with MSCT was higher than that of US alone and MSCT alone (P<0.05). Conclusion The application of abdominal ultrasound combined with CT in clinical diagnosis of patients with gastric cancer has significant positive effect. It greatly improves the accuracy rate of preoperative staging diagnosis and can provide guidance for the development of operation plan. It is of great value