The embodiment of the invention provides a charging method and device. The charging method is characterized in that the charging for a battery includes a first charging stage and a second charging state, wherein the first charging state comprises at least two charging sub-steps; the battery is sequentially subjected to first constant-current charging, second constant-current charging, constant-current discharging and third constant-current discharging in each charging sub-step; the battery is subjected to constant-voltage charging in the second charging state. According to the technical scheme provided by the embodiment of the invention, the charging method and device can solve the problem of high safety risk, caused by the increase of the charging speed, of the battery in an existing charging method, can be solved.