Break-away coupling is a key equipment to prevent the leakage caused by the hose breaks unexpectedly. According to the filling permission rules for mobile pressure vessels, the emergency shut-off device should be installed on the liquid pipeline of the truck filling station. At present, there is little experience in application of break-away coupling in the loading arm, and the existing experiment is only for the individual of the break-away coupling. There are doubts about its safety and reliability, while the field testing with arm and liquid may cause damage to equipment and large-scale leakage, as well as the economic and security costs. In response to this situation, taking the load-arm break-away coupling of Shandong LNG as an example, the finite element model of break-away coupling is established by LS-DYNA, and the simulation results under the design parameters and actual working conditions are given. Several recommendations are made for the design and application of break-away coupling.