The invention discloses a charging method of a battery. The method comprises: segmented constant-current charging is carried out on a battery, wherein the segmented constant-current charging at least includes a process of constant-current discharging on a battery; and the process is carried out circularly until a charging cut-off voltage of the battery is reached, and then constant-voltage charging is carried out on the battery. Therefore, polarization generated by battery charging can be eliminated by means of constant-current discharging, so that the polarization elimination effect is obvious; the time of reaching the charging cut-off voltage of the battery is prolonged; and the time at a segmented constant-current charging stage is prolonged, so that the charging efficiency is improved and thus the full battery charging time is shortened. Meanwhile, because of timely polarization elimination, battery heating phenomenon occurrence is reduced and the security performance of the battery is protected.