Objective:To establish an accurate C57BL6/J mouse model of acute radiation-induced enteritis based on small animal radiation research platform (SARRP).Methods:Forty-eight female mice were randomly divided into the following four groups: blank control group, 6 Gy irradiation group, 9 Gy irradiation group and 12 Gy irradiation group. Based on the SARRP, the mice in the irradiation groups were exposed to a single fraction dose of 6 Gy, 9 Gy and 12 Gy at a dose rate of 4Gy/min, respectively. The general condition, body weight and pathological changes of the small intestine of mice were observed.Results:After CT scanning, the target area and normal tissues were delineated. According to the dose distribution of the target area and the protection of spinal cord, the AP-PA field irradiation scheme at the isocentric level was adopted. The average irradiation time in the 6, 9 and 12 Gy groups was 163, 252 and 328 seconds, respectively. The survival rates of mice in the 6, 9 and 12 Gy groups were 100%, 100% and 50% 15 days after irradiation.The body weight of mice in the 6 Gy ( P=0.035), 9 Gy ( P=0.002) and 12 Gy groups ( P<0.001) was decreased significantly on the 5 th day after irradiation, and gradually increased on the 10 th day. With the increase of irradiation dose, the villus and gland injury was aggravated. Compared with the blank control group, the villus length in the 9 and 12 Gy groups was significantly shorter (both P<0.001), and the intestinal wall thickness in the irradiation groups was significantly thinner (all P<0.001). Conclusion:SARRP can provide accurate target location, planned screening and accurate dose delivery in the establishment of C57BL6/J mouse model of acute radiation-induced enteritis. The C57BL6/J mouse model of acute radiation-induced enteritis can be successfully established by a single fraction total-abdominal irradiation of 6-9 Gy.