The wave of Industry 4.0 drives the development of intelligent manufacturing. A modern precast girder yard is a complex system that collects multiple elements such as intelligent sensing equipment, construction personnel, facility instruments, and data processing platforms, etc. The existing management platform has problems such as scattered management processes, poor integration, and poor delivery efficiency, etc. How to promote the interaction and collaboration of complex systems and increase the yield of precast girder yards is the current challenge for enterprises and researchers. This paper adopts a model-based system engineering approach to model the system requirements, system environment, system architecture, subsystem interactions and functions of the smart girder yard, and combines digital twin technology to build a digital twin of the physical girder yard, thus realizing visualization of girder yard production, construction simulation and intelligent scheduling decisions. Through system verification, the application of the smart girder yard system reduces the interference of human factors in the production schedule of the girder yard, improves the production efficiency, and meets the requirements of digital control of all elements of the production schedule.