A charging method and system applied to the field of mobile terminals. The charging method comprises: a cell detection circuit acquiring a voltage value of a cell and sending the acquired voltage value of the cell to a second controller; the second controller finding from a threshold value section table a current regulation command that is matched with a threshold value section in which the voltage value of the cell is located, and sending the current regulation command to a regulation circuit, wherein the threshold value section table records one or more threshold value sections and current regulation commands having a mapping relation with the threshold value sections; and the regulation circuit performing current regulation according to the current regulation command, and outputting a power signal after the current regulation. By means of the charging method, the charging current flowing into the cell can be regulated in real time, so that over-charging of the cell can be avoided; a charging circuit in a mobile terminal and a charging circuit in a charging adapter can be protected.