The invention relates to an automobile failure detection system based on cloud calculation. The automobile failure detection system solves the problems that a general automobile does not have a function of automobile failure detection or is not specific in failure detection, and users cannot maintain the automobile timely, so that safety hazard is added, simultaneously the failure can be serious, and maintenance cost is added. The automobile failure detection system comprises a vehicle-mounted terminal and a cloud calculation side, wherein the vehicle-mounted terminal comprises an automobile data communication interface module, a control module, a network communication module and a display module, and the vehicle-mounted terminal is connected with the cloud calculation side through a network. The automobile failure detection system based on cloud calculation has the advantages that the sensor technology, the wireless network technology and the cloud calculation technology are integrated, the automobile only needs to be installed a simple vehicle-mounted terminal, specific failure diagnosis is completed by the cloud calculation side, and the automobile failure diagnosis function can be achieved with no need of installing a failure diagnosis instrument, so that users can timely maintain the automobile, maintenance cost and safety hazard of the automobile are reduced, simultaneously the structure of the automobile is simplified, and purchasing cost is reduced.