With the development of bridge construction, none of the traditional approaches, i. e. bar chart and network diagrams, etc. , has the capabilities to match the development of construction management. Combined the object-oriented system simulation technology for complex engineering system with the CAD digital modeling technology, the system simulation of bridge construction based upon 4D CAD was presented, which linked a 3D model of a construction project with a project activity schedule element. The dynamic visualization of construction process and intuitive analysis on the optimization of construction schemes were achieved. And the corresponding software of visualization simulating system, based on 4D CAD, for construction of bridges was programmed with visual C++. The successful application of the software to the practical cable-stayed bridge showed the practicality and preponderance of this method.