Abstract: A method and system for detecting and locating trapped people are provided. The method includes the following steps: (a) transmitting a first wireless signal based on a transmission power, and recording the transmission power; (b) when a first mobile device registers to the system for detecting and locating trapped people in response to the first wireless signal, recording identity information of the first mobile device; (c) determining whether the transmission power is a maximum transmission power; (d) if no, increasing the transmission power, and repeating the steps (a) to (d); if yes, calculating a relative location between the first mobile device and the system for detecting and locating trapped people based on the recorded transmission power and the recorded identity information.