Objective To explore the ultrasonic and MRI manifestations of enlarged iliopsoas bursa,and provide help for clinical correct treatment. Methods From January 2017 to may 2019 , 84 patients (93 hips) with EIB were analyzed retrospectively. The diagnostic coincidence rate of EIB, the classification of hip joint effusion and the difference of measurement parameters of iliopsoas capsule were observed. Results ① the positive rate of ultrasonography was 81.72% (76 / 93), which was significantly lower than that of MRI (P < 0.001). ② There was no significant difference between ultrasound and MRI in the evaluation of hip effusion (P > 0.05). ③ There was no significant difference in the measurement parameters of iliopsoas bursa between the transverse diameter and sagittal diameter (P > 0.05), while in the measurement of longitudinal diameter, MRI was significantly greater than ultrasound (P < 0.05). Conclusion Ultrasound could provide the basis for the early diagnosis of EIB, but we should be familiar with the anatomy around the hip and the corresponding examination technology, and make clear the pathogenesis and the prone position of EIP. At the same time, combined with the medical history, physical examination and other data to make a comprehensive judgment.