The invention discloses an automobile detecting system based on a sensing technology. The automobile detecting system comprises a vehicle-mounted terminal, a cellphone terminal and an assisting terminal, wherein the vehicle-mounted terminal comprises a human body infrared sensor, an oxygen concentration detecting module, a temperature detecting module, a data processing module, a switch control module, a power source module, an air-conditioner system, a timing module and a central control module; the cellphone terminal comprises a first cellphone client-side and a second cellphone client-side; and the assisting terminal comprises an alarming module. According to the automobile detecting system disclosed by the invention, through the systematic structure design of the vehicle-mounted terminal, the cellphone terminal and the assisting terminal, the oxygen concentration and the temperature in an automobile are detected in time, once the oxygen concentration or the temperature exceeds corresponding threshold value, the automobile can send alarming information to the owner of the automobile and outside the automobile, so that a response can be performed in time, the irreparable harm to children because of the changes of the temperature and oxygen deficiency is avoided, potential safety hazards are effectively eliminated, and the occurrence of safety accidents is reduced.