Objective To investigate the effectiveness and safety of different sedation methods for magnetic resonance imaging (MRI) examination of the urinary system in children after drinking water. Methods Children who received sedative treatment for urological MRI examination at the Sedation Center of Children's Hospital Affiliated to Shandong University from January 1, 2021 to November 31, 2022 were selected as subjects. Their medical records were collected by retrieving the electronic medical record system and the sedation management system. According to their corresponding sedation methods, the children were divided into two groups: an oral midazolam + dexmedetomidine nasal drip group (group PO) and an intravenous midazolam+propofol group (group IV). The propensity score was used to match the relevant variables, and 88 pairs were successfully matched. Both groups were compared for general information [gender, age, weight, and American Society of Anesthesiologists (ASA) grades], the success rate of one-time sedation, the time to fall asleep, the time to awaken, the duration of examination, and the incidence of adverse reactions. Heart rate, pulse oxygen saturation (SpO2) and respiratory rate (RR) were analyzed before medication (T0), immediately after sleep (T1), at the beginning of examination (T2) and immediately after awakening (T3). Results After propensity score matching, there were no statistical differences in gender, age, weight, ASA grade, the success rate of one-time sedation, and the duration of examination between the two groups (all P>0.05). Group PO showed significantly longer time to fall asleep and awaken than group IV (all P<0.05). Group VI also presented significantly lower heart rate than group PO at T3 (P<0.05), and lower RR than group PO at all the time points (all P<0.05). There were no statistical differences in SpO2 between the two groups at all the time points (all P>0.05). Compared with those at those at T0, both groups showed decreases in heart rate, SpO2 and RR at T1 to T3, and the differences were statistically significant except for RR in group IV at T3 (all P<0.05). Compared with those at T1, SpO2 and RR in group PO and RR in group IV increased at T3 (all P<0.05). Compared with those at T2, RR in both groups increased at T3 (all P<0.05). All the children successfully completed MRI examination, including four cases of decreased heart rate and one case of irritability during the awakening period in group PO, and one case of decreased heart rate in group IV, there was no significant difference in adverse reactions between the two groups (all P>0.05). Conclusions Both oral midazolam combined with dexmedetomidine nasal drip and intravenous midazolam combined with propofol are safe and effective for urinary MRI examination of the urinary system in children after drinking water, with a high success rate, fewer adverse reactions, and without reflux aspiration.