In order to study the effect of particle radius、particle concentration and charge number of charged dust in dusty plasmas on the performance of quantum communication, according to the Mie scattering theory, the light scattering cross section of single charged dust particle was obtained. Based on particle concentration, the extinction cross section of particles was calculated, the mathematical model of the link attenuation was established, and the relationship between the characteristics of charged particles and quantum entanglement was proposed. Aimed at the depolarization channel, when the number of charged particles adsorbed by a dust particle is 50, the quantitative relation among the dust particle radius and the particle concentration, the channel capacity and the quantum bit error rate was given. The simulation results show that when the transmission distance of quantum signal is 10km, particle concentration increases from 1×1010 m-3 to 10×1010 m-3, the channel capacity decreases from 0.672 6 to 0.107 5; the dust particle radius increases from 0.1 μm to 10 μm, the quantum bit error rate increases from 1.334×10-3 to 5.309×10-3. It can be seen that the radius and concentration of charged dust particles in the plasmas have a significant influence on the performance of free space quantum communication. Therefore, in order to ensure the reliability of quantum communication, the various parameters of the communication system should be adjusted according to the conditions of the detected plasmas environment.