Abstract: A high falsework system which is intended to prevent progressive collapse is proposed. It is composed of a single-function subsystem and a dual-function subsystem. The two subsystems work together under normal design situation (first stage). Once the single-function subsystem fails accidentally, the dual-function subsystem can work alone to avoid progressive collapse of the whole system (second stage). Considering the differences of the two stages in the settlement, load and function, the target reliability indexes of the two-stage design are discussed and proposed. Reasonable constructional measures and types of shores are obtained considering both the ultimate capacities and the amount of material. The system not only satisfies the requirement of structural safety in normal design situation, but also provides opportunities for workers to escape and rescue channels for lifesaving when accidents happen.