An abnormal battery detecting system for an electric vehicle includes a power supply unit, a displaying unit, a battery module, a safety protection unit, a detecting unit, and a controlling unit. The battery module a main power source of the electric vehicle. The safety protection unit is connected with the battery module and the power supply unit. The detecting unit is connected with the battery module and the power supply unit for detecting the battery module. If the battery module is abnormal, the detecting unit generates at least one feedback signal that is received by the controlling unit. The controlling unit compares the feedback signal with at least one preset default value and generates an abnormal level signal to the displaying unit and the safety protection unit. The safety protection unit is selectively enabled to control an operation of the battery module according to the abnormal level signal.