Traditional electrochemical analysis techniques cannot fully reflect the electrochemical process of organic coating corrosion. Hence, distribution of relaxation time (DRT) technique was adopted to fit the electrochemical impedance spectrum (EIS), meanwhile, the distribution of relaxation time of the long-term anticorrosion process of polydimethylsiloxane coatings without and with artificial scratches was investigated, in other word, the later one experienced self-healing cycles. The results show that the function of the EIS itself as a whole and the contribution proportion of each element of the EIS of the coating during the corrosion process can be clearly analyzed via the DRT technique combined with equivalent circuit model analysis. Meanwhile, the corresponding relaxation time of each element in EIS equivalent circuit was discussed theoretically. This paper provides a new analytical technique for corrosion electrochemical mechanism study.