Objective To investigate the value of MRI in detection rate, morbidity and mortality in elderly patients with multiple cerebral infarction. Methods The clinical data of 100 elderly patients with multiple cerebral infarction admitted to our hospital from January 2015 to January 2017 were retrospectively analyzed. Among them, 52 patients in the control group were diagnosed by CT, and 48 patients in the observation group were diagnosed by MRI. The lesion detection rate, morbidity, mortality, examination indicators and site abnormalities were compared between groups. Results The lesion detection rate and the attack rate within 24h in the observation group were higher than those in the control group (P<0.05), and the attack rate during 24h-72h and more than 72h in the observation group were lower than those in the control group (P<0.05). The lesion detection rate within 6h in observation group was significantly higher than that in control group, and the morbidity and mortality in the observation group were lower than those in the control group (P<0.05). The number of lesions in the observation group was larger than that in the control group (P<0.05). The size of the lesion and the examination time in the observation group were shorter than those in the control group (P<0.05). The site abnormalities showed a significant difference between the two groups (Z= -8.609, P=0.000). Conclusion MRI can improve the detection rate of senile multiple cerebral infarction lesions, and reduce the morbidity and mortality, which is worthy of recommendation.