The reasons of ice blockage in the g as pipeline we re analyzed, and some methods to measure the ice blockage were simply introduced. Some drawbacks in these methods were pointed out. A method to detect position of ice blockage using gas - emitting sound wave was presented. The research indicates that the sound signals obtained from the ice blockage position are random , and various sample recordsin the random progress are not same , so mathematics formulae do not express the relationship. However , those samples have the same statistic properties, and can be expressed by probability statistics. As the amount of sound wave data is big , the process of analyzing the data is very complicated. Through the mathematics deduction of sound wave detecting method, an experiment equipment detecting ice blockage position with sensors was designed and its work principle was introduced in details. In the experiment process , the sound around the pipelines was considered, and the principle to remove noise by wave filtering was researched.