A terminal and a fast charging method to fast charge the terminal, where the method includes sending, by the terminal, instruction information to a charger connected to the terminal in order to instruct the charger to adjust an output voltage and an output current, converting, by the terminal, the output voltage of the charger into 1/K times the output voltage, and converting the output current of the charger into K times the output current such that a charging circuit between two sides of a battery charges the battery with the 1/K times the output voltage and the K times the output current, where K is a conversion coefficient of a conversion circuit with a fixed conversion ratio in the terminal and is a constant value, and K is any real number greater than one.