Objective: Laser confocal microendoscopy (CLE), as one of the auxiliary method for precise mucosal biopsy for ulcerative colitis (UC) and evaluation of intestinal barrier function, has achieved many clinical data. This study optimized the previous CLE mucosal healing score in order to obtain a fast and convenient scale to assist in the determination of deep remission of UC. Method: Reviewing the CLE images of UC patients in clinical remission or mild active stage who underwent CLE examinations continuously at Peking University First Hospital from January 2017 to December 2019, as well as healthy individuals who underwent CLE during the same period. Based on previous studies, potential typical CLE image changes in UC were listed as the typical CLE image indicator observed in this study. By comparing with healthy controls and UC inflammation uninvolved intestinal segments, typical CLE images indicator with detected differences were obtained, and univariable regression analysis was used to obtain CLE image indicators related to histological remission (Geboes score), forming a simplified CLE score using the significant factors . Find the decision point of simplified CLE score for determination of UC deep remission by ROC curve. Result: Fifty-three UC patients and 14 healthy individuals were included in the study, a total of 201 segments of CLE images. Among the 8 items of typical CLE image indicators with significant differences detection rate, including crypt deformation, crypt lumen deformation, crypt proximity, crypt sparsity, crypt fluorescein leakage, vascular fluorescein leakage, vessel diameter thickening and cell infiltration. Univariable analysis related to histological inflammation detected that there were 4 items of above 8 CLE image indicators related to Gebose score≤2.0, including crypt deformation(p=0.025, OR=3.613, 95%CI: 1.174-11.114), crypt lumen deformation(p=0.021, OR=4.081, 95%CI: 1.233-13.511), crypt fluorescein leakage(p=0.011, OR=5.486, 95%CI: 1.468-20.494) and vessel diameter thickening(p=0.002, OR=7.724, 95%CI: 2.062-28.938). The decision point for simplified CLE deep remission score was described as none of the 4 items of CLE image indicator appeared. ROC curve was plotted with AUC of 0.769 and a 95%CI of 0.654 to 0.833. The sensitivity and specificity of the decision point as to determine the deep remission of UC by CLE were 83.1% and 42.1%, respectively. Conclusion: With a high sensitivity and positive correlation with pathological deep remission, the simplified CLE score can be used as an important auxiliary method for determination of UC deep remission.