The primary goal of this paper is to address the challenges associated with the design and application of a practical wireless measurement system for the continuous safety monitoring of a large-scale structural members under construction. A practical wireless sensor network system (WSNS) was designed and real-time structural health monitoring (SHM) on long–span girders in a building under construction was performed. A WSNS consists of vibrating wire strain gauges (VWSGs) along with a sensor node, a master node, and a monitoring server. The field application of the WSNS using WVWSs was conducted on long-span plate girder and beam members of the K Art Hall during the construction of the building. It was possible to monitor the strain changes of the long-span plate girders and beams in real time as a function of the construction process and temperature changes.