The utility model discloses a safety air bag positioning system based on an automotive OBD (on-board diagnostics) interface. The safety air bag positioning system comprises a safety air bag control chip (1), the OBD interface (10), a main control chip (2), a GPS (global positioning system) (3), a storage unit (4) and a GPRS (general packet radio service) module (5), wherein the main control chip (2) is connected with the OBD interface (10), the GPS (3), the storage unit (4) and the GPRS module (5) respectively; the safety air bag control chip (1) is connected with the OBD interface (10). According to the safety air bag positioning system disclosed by the utility model, accurate and real-time transmission for car accident information is realized, so that casualties can be effectively treated and cured at the first time. In addition, the safety air bag positioning system disclosed by the utility model is small in volume, low in power consumption, low in cost, high in information transmission accuracy, and suitable for large-area popularization and application. Moreover, according to the safety air bag positioning system disclosed by the utility model, the condition of a car accident is judged by obtaining the state information of a safety air bag through the OBD interface, so that the misjudgment rate is almost zero.