AP1000 is the third-generation nuclear power technology introduced from Westinghouse in China. The CAP nuclear power is the third-generation nuclear power technology that is based on the digestion and absorption of AP1000 nuclear power technology and has independent intellectual property rights. As ASME code class I component,in order to ensure the smooth development at site and meet the installation quality of the main pipe,a physical simulation of 1:1 ration is conducted before the formal installation,which is to simulate the process of machining,fitting,and welding about single loop main pipe. Through the 3D modeling technology,the construction process is monitored in real-time,the control measures,crafts and results meeting design requirements is verified,so as to accumulate experience for the formal construction of the main pipeline.