The invention discloses a battery open circuit voltage estimation method based on binary coding, which belongs to the technical field of electric vehicles. The method comprises a first-order RC equivalent circuit model parameter recognition stage and a battery open circuit voltage predication stage. The first-order RC equivalent circuit model parameter recognition stage comprises steps: 1, a first-order RC equivalent circuit model for describing battery dynamic characteristics is built; 2, and according to actually-acquired battery current and voltage signals, model parameters are predicted based on a least square method. The battery open circuit voltage predication stage comprises steps: 3, a multi-order RC equivalent circuit model for describing battery static characteristics is built; 4, R1C1 recognized by the first-order RC equivalent circuit model parameter recognition stage serves as a reference R0C0; 5, RiCi in the multi-order RC equivalent circuit model is made to be 2iR0C0; and 6, according to the least square method, battery open circuit voltage is recognized. A binary coding principle is introduced to predict the battery open circuit voltage, and the problem that as the multi-order equivalent circuit model is high in linearity and high in coupling, solution is not facilitated can be solved.