Abstract: Pipeline installation in mountain's steep slope has always been a difficult construction process. This paper introduces the principles and process flow of pipe-slipping installation technology, and highlights the connection method between pipe section and traction device and inplace process of slipping down along the pipe sections of straight pipe trench and of horizontal bending pipe trench in illustration way. The results from analysis and overview on the technology application in the 2nd West-to-East Gas Pipeline Project show that this technology can override the barriers in front of the pipeline installation at steep slope in mountain, shortening the construction period and lowering construction costs, thus achieving good economic and social benefits.