The invention provides a combined bursting disc safety device for a high-pressure natural gas long pipe trailer and an application method thereof, and belongs to the technical field of safety and explosion protection of a high-pressure gas cylinder with a flammable and explosive medium. The combined bursting disc safety device for the high-pressure natural gas long pipe trailer comprises a combined bursting disc holder, a pressure sensor, an intelligent controller, a wireless transceiving module, a mobile receiving end and a long pipe trailer moving safety monitoring platform, wherein the intelligent controller is connected with the pressure sensor, and the intelligent controller comprises a data acquisition module, a data storage module and a data processing module; and the intelligent controller is used for sending information with pressure parameters of interior of the holder to the long pipe trailer moving safety monitoring platform after processing. According to the combined bursting disc safety device for the high-pressure natural gas long pipe trailer, not only is the high risk of the single-layer bursting disc avoided, but also potential safety hazards existing in the easy-melting plug device of the bursting disc are avoided, the new device is monitored in real time, and safety of the device is greatly improved.