The present disclosure provides an accident alert system for preventing secondary collisions. The system for preventing a secondary accident comprises a terminal configured to have a global positioning system (GPS) navigation capability, monitor and display a driving state and an accident state of a vehicle, transmit information on a driving state and the accident state via a communication network, and display information received on a screen; and a server platform configured to exchange information with the terminal, include an algorithm for determining the occurrence of an accident based on the information on the driving state and the accident state received from the terminal and traffic information, and inform other terminals of the occurrence of the accident.