Numerical simulation for the development of K-H(Kelvin–Helmholtz) instability of the three-component immiscible fluids had been performed with the Front Tracking Method (FTM). This study focuses on the effect of density and viscosity of intermediate fluid layer

the gravity

surface tension and shear force on K-H instability. It is found that the Richardson number(Ri) not only inhibits the evolution of interface but also limits the degradation of interface. It is also observed that the Froude number is positively correlated to the billow height and the numerical growth rate. The influence of surface tension on the inward development of K-H instability is more important than that on the upward development of K-H instability if the wave number is not very large. Besides

the typical form of K-H instability is not triggered when the wave number greater than 4. The larger the shear force is

the bigger billow height and numerical growth rate of interface is.