Earthquakes, typhoons and many natural disasters often cause comprehensive damage and destruction to human life and health in a very short time. The survivors of natural disasters bear physical and mental damage, which increases the risk of death. Particularly, the middle-aged and elderly are most vulnerable after natural disasters, due to their weakened physiological conditions. Their demand for medical care is also higher than that of other age groups. Most past work addressed the immediate impact of disasters on the morality risk of survivors, while little literature has focused on the aftermath of natural disasters to the morality risk of survivors. In this study, we use the National Health Insurance database and explore the mortality risk of the 921 Chi-Chi Earthquake's survivors. Specifically, we study the mortality risk of earthquake survivors aged 50 and beyond in Nanto and Taichung counties (the disaster area), and compare them with those in Changhua county (a non-disaster area). The major findings include the face that the earthquake caused severe casualties within a short period of time, yet the survivors still had higher a mortality risk, which was about 1.27 times higher than that of the people of the non-disaster area for the first 3 months after the earthquake, and 1.16 times higher one year later. This suggests that the earthquake's effect on the mortality risk did not disappear immediately after the disaster and, in fact, lasts almost one year. Our results can provide the government with some policy implications regarding the assessment of emergency medical care and long-term care for the elderly.