Numerous engineering practices show that construction safety risks are influenced by many factors, which are sometimes intertwined and difficult to distinguish. Risk factors, as part of the risk system, will inevitably have connections and interactions with other parts of the system. Risk factors or risk events that move up the risk-causing pathway to higher levels are risk factors acting on the risk system in a logical progression, an evolutionary and developmental process. When there are multiple risk factors in the risk system, the effect of each risk factor on the risk system during its evolutionary development process is often influenced by other risk factors, making the effects of each risk factor “indivisible” and unable to be viewed independently. From the original definition of the term “coupling”, the combined effect of risk factors on the risk system during their evolutionary development process is a manifestation of a coupling phenomenon.