A method of controlling a hard disk and an electronic device, comprising: determining a number of power cycles that have been completed by the hard disk at a time point within a predetermined period of time, a power cycle including a total duration of the hard disk in a spin-on mode and an immediately neighboring spin-off mode; and in response to the number of power cycles that have been completed being below an upper limit number for the power cycles of the hard disk in the predetermined period of time, determining remaining time of the predetermined period of time starting from the time point, and determining, based on the remaining time, the number of power cycles that have been completed, and the upper limit number, a threshold idle duration for controlling the hard disk to enter the spin-off mode.