It is still an open question that how the masses are formed for charged leptons. The widely accepted Yukawa coupling mechanism generally have quite randomized coupling constants for their masses. In this paper, we tried to build a simple model to calculate the masses of charged leptons. We assumed that the masses are formed by coupling of the plasma characteristic energy from the particle-antiparticle pairs in the background sea, and the electric potential inside the Compton ball. The internal structure of the charged leptons is thought to have three states, i.e. the negative charge, the positive charge and the Planck scale Kerr black hole. For electron and muon, the zitterbewegung is formed by positive charge and negative charge, but for tau, the excited zitterbewegung is formed by negative charge and the Planck scale Kerr black hole. The calculations of this simple model give quite close values for the charged leptons as compared with the lab results. We think we may need pay more attention on the internal structure of a particle.