Objective To explore the clinical application value of real-time continuous glucose monitoring system (RT-CGMS) in the treatment of patients with diabetes mellitus complicated with multiple organ dysfunction syndrome (MODSE) in the elderly of Bai Ethnic Minority. Methods From January to December 2018,112 elderly patients with diabetes mellitus complicated with MODSE admitted to People′s Hospital of Dali Bai Autonomous Prefecture (APACHE Ⅱ score >15 points) were enrolled and then randomly divided into RT-CGMS group (n=56) and self-monitoring blood glucose group (SMBG group, n=56). The general clinical data, blood glucose fluctuation index, incidence of hypoglycemia, average daily insulin dosage, length of hospital stay and 28-day mortality were compared between the two groups. SPSS statistics 16.0 was used to perform the statistical analysis. Student′s t test or Chi-square test was employed for comparison between the two groups. Results The standard deviation of blood glucose (SDBG) was decreased from (3.2±1.1)mmol/L on the second day to (2.9±1.0)mmol/L on the third day of the treatment in the SMBG group (P<0.05), and in the RT-CGMS group, the mean blood glucose (MBG) was reduced from (10.8±2.5) to (8.8±1.9) mmol/L, SDBG from (2.8±0.8) to (1.8±0.7)mmol/L, largest amplitude of glycemic excursion (LAGE) from (8.9±3.6) to (7.2±1.6) mmol/L, and mean amplitude of glycemic excursions (MAGE) from (6.3±1.0) to(5.0±0.4) mmol/L (all P<0.05). On the second day, the decrease of SDBG was more obvious in the RT-CGMS than the SMBG group [(2.8±0.8) vs (3.2±1.1)mmol/L, P<0.05). While, on the third day, the RT-CGMS group had more significant decrease in MBG [(8.8±1.9) vs (10.9±2.8) mmol/L], SDBG [(1.8±0.7) vs (2.9±1.0)mmol/L, and LAGE [(7.2±1.6) vs (9.6±3.1) mmol/L] when compared with the SMBG group (P<0.05). What′s more, the incidence of hypoglycemia (3.6% vs 16.1%), average daily insulin [(32.1±5.4) vs (38.2±6.8) IU/d] and length of hospital stay [(12.1±4.0) vs (14.6±4.2) d] in the RT-CGMS group were notably lower than those in the SMBG group (P<0.05). Conclusion The application of RT-CGMS can reduce the fluctuation of blood glucose in Bai elderly diabetic patients complicated with MODSE, and show important clinical significance in improvement of rescue success rate, prolongation of survival period, and decrease of average length of hospital stay.