Objective To analyze the application value of MRI (magnetic resonance imaging), CT and ultrasound in the diagnosis of insulinoma. Methods Seventy-two patients with insulinoma who underwent surgical treatment in our hospital were enrolled in the study. All subjects underwent MRI, CT and abdominal ultrasonography, and the results were compared with the operation results to analyze the site and size of lesions. The imaging findings were also compared. Results MRI, CT and ultrasound respectively detected 58 cases, 46 cases and 44 cases of lesions, and the incidence rates were 80.5%, 63.9% and 61.1%, respectively. The site and size of insulinoma showed no significant difference (P>0.05). The detection rate of MRI was the highest (P<0.05). MRI scan showed abnormal signal on T1WI, T2WI and DWI, obvious enhancement in dynamic enhancement phase. CT showed 32 cases in arterial phase, more than those in portal vein phase, and 12 cases showed slight enhancement in arterial phase and portal vein phase;Ultrasound showed clear boundaries, visible tumor and vascular site. Conclusion The detection rate of MRI is the highest but expensive. The detection rate of CT is similar to that of ultrasound but the ultrasound is easy to be interfered by gastrointestinal gas, affecting the results. Therefore, the best diagnostic method should be chosen according to the actual condition.