Abstract: The 2nd West-to-East Gas Pipeline mainly transmits gas from central Asia. In order to avoid insufficient offtake throughput or serious shutdown event caused by ice blockage, the reasons of ice blockage is analyzed that that includes large offtake pressure differences, large fluctuating temperature drop and higher water dew point. The changes of parameters, such as pressure behind pressure regulating valve and the opening, offtake outlet pressure, and flowrate, are used to determine if initial ice blockage is formed. Logic operations on the pressure behind pressure regulating valve and offtake outlet pressure are conducted to obtain the initial ice blockage position. Moreover, Logix5000 software is applied for realizing logic of SCADA-based ice blockage warning. Field simulation results show that this method can effectively provide prediction and warning of ice blockage in different regions of offtake terminals. So, it is a good reference for the prevention of ice blockage of nature gas pipeline.