Objective To explore the clinical significance of B-ultrasound, MRI and hysteroscopy in the diagnosis of uterine space occupying lesions. Methods 108 patients with suspected uterine space occupying lesions admitted to our hospital from January 1 to December 31 2017 were selected as the study objects. All patients were examined by vaginal color Doppler ultrasound, MRI and hysteroscopy before uterine operation. Compared with the results of pathological examination, the sensitivity and specificity were analyzed. Results Among the 108 patients, 27 had no pathological changes in uterine cavity, 39 had endometrial polyps, 27 had endometrial hyperplasia, 10 had submucous myoma, and 5 had endometrial cancer. The sensitivity of B-ultrasound, MRI and hysteroscopy were 72.84%, 71.60% and 75.31% respectively, and the specificity were 62.96%, 85.19% and 66.67% respectively. The sensitivity of B-ultrasound+MRI in the diagnosis of submucous myoma and endometrial carcinoma was 100% and the specificity was 87.76% and 99.03%, respectively. The sensitivity of B-ultrasound+MRI+hysteroscopy in the diagnosis of endometrial hyperplasia, submucous myoma and endometrial carcinoma was 100%. Conclusion Most of the uterine space occupying lesions are benign. B-ultrasound combined with hysteroscopy and MRI may improve the diagnosis rate. The high-risk group of endometrial cancer should be examined by B-ultrasound and MRI, and hysteroscopic biopsy would be performed only when necessary.