The invention discloses a method for intelligently controlling multimedia playing, which is characterized in that: an earphone is provided with a pulse-detecting sensor, which generates a signal every time one pulse is detected and then transmits the signal to a mobile terminal; and an option for a sleep mode is set at the mobile terminal, when the sleep mode is selected, the mobile terminal acquires real-time heart rate of the user based on the pulse times detected by the sensor within unit time and controls own multimedia playing after determining that the user falls asleep according to the change of the heart rates prior to and subsequent to the sleep of the user. The invention simultaneously discloses a system and an earphone for intelligently controlling multimedia playing; according to the proposal of the invention, multimedia playing can be precisely and intelligently stopped once the user falls asleep, thus the harm of the multimedia playing earphone to human ears during sleep is reduced, the sleeping quality of the user is enhanced, the standby time of the mobile terminal is prolonged, and simultaneously, health information can also be provided for the user in real-time.