Abstract: An engineering construction system is a complex one which involves multi-stage and multi-construction tasks as well as multi-equipment matching. With regard to the risks caused by the equipment matching failures in a complex construction system, a binary decision diagram method is applied to analyze the matching reliability between tasks and equipments in this study. Firstly, a hybrid diagram with the mixed series-parallel structure (cascade and multiple) is abstracted from each stage of the construction system and a fault tree is built, and then the fault tree is simplified through the simultaneous component failure. Based on the recursion method, the simplified fault tree is transferred to the binary decision diagram method. Finally, the probability sum of non-intersect branch pointing to “0” in the binary decision diagram from the above steps is the reliability of both the equipment matching system and the tasks. This method, with lower computation complexity, applicable in practical projects, and reasonable in analysis results, can effectively solve the risk problems during failures in the complex construction system, has the value of extensive application in the civil engineering construction in the future.