Through analysis and study of relevant technical data from the research results, actual engineering and working experience for the application of flyash as the filling material for embankment both at home and abroad, this paper introduces the basic characteristics, compaction performances and mechanical properties of flyash, and it provides the relevant technical indexes, structure and form of embankment design and related technical parameters for the application of flyash as filling material for railway embankment. It can be referred for the similar engineering.