Collapse is one of common geological hazards in pipeline construction under complex geological conditions. Classified are common dangerous rock masses in pipeline construction according to its potential instability pattern, DDA numerical model analysis method is applied to research the formation mechanism of instability pattern of different dangerous rock masses, static analytic calculation method is applied to establish mechanics model. Introduced are stability evaluation methods of different dangerous rock masses in working conditions with no external force, earthquake and rainstorm, which provides basis for selection of pipeline route, construction and operation and maintenance of pipeline.