In order to study the interaction between millimeter wave and plasma, by using time-domain integration method to simulate the attenuation characteristics of millimeter wave propagation in the plasma ,this paper makes preliminary study on the relationships betwcen the attenuation value of millimeter waves propagation in the plasma, plasma density, the collision frequency and operation frequency. By comparing and analyzing the theoretical results with simulation results, the feasibility of the fact that simulation can be used to provide data support for the theoretical study is verified.