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.