In order to analyze the factors of foam lightweight soil embankment stability， calculation model using ANSYS， based on strength reduction femto study the influences of density， cohesion and internal friction angle of foam lightweight soil on foam lightweight soil embankment stability，then the sensitivity analysis to each factor is carried out， and the stability of the foam lightweight soil embankment and the common soil embankment is compared.The results show that density and cohesion of foam lightweight soil are two important factors of embankment stability；when the design density of the foamed lightweight soilislessthan6kg/m， the cohesion isabove 60kPa， the safety factor of embankment with different heights is greater than com-mon soil embankment， and can meet the requirement of 16m high embankment stability.The control standard of cohesion for foam lightweight soil of different height embankment under different density(600， 800， 1100kg/m) was proposed.