The interaction between rainfall and aircraft wake vortices changes their dynamic characteristics， and the dynamic evolution of wake vortices， which has an important impact on the safety of wake encounters. Aiming at the interaction between wake vortices and rainfall， this study investigates the evolution characteristics of wake vortices in rainy conditions based on the Euler-Euler multiphase flow model. For the air phase simulation in the multiphase flow model， the large eddy simulation turbulence model is used. The dynamic transport of rain phase is controlled by two scalar equations. The two phases are coupled through the momentum source term to realize the energy transfer. The influence of rainfall rate on the evolution characteristics of wake vortices， such as circulation， vorticity， velocity distribution near the vortex core and sinking velocity， is analyzed. The results show that rainfall accelerates the decay of the circulation， reduces the maximum vorticity of the vortex core， smooths the velocity distribution， and affects the descent process of wake vortices. In addition， the presence of wake vortices also affects the trajectory and concentration distribution of rain.