A screen ON-and-OFF state control method realized by a mobile terminal (400; 500), wherein the mobile terminal (400; 500) comprises a processor and a memory, the screen ON-and-OFF state control method comprising: a step of, during a distance detection through a far-channel Infrared - IR detection, when a timing start condition for a near-channel IR detection has been met, interrupting, by the processor, the far-channel IR detection, and enabling the near-channel IR detection for the distance detection; and a step of controlling, by the processor, ON and OFF states of a screen of the mobile terminal (400; 500) in accordance with a distance detection result of the near-channel IR detection, wherein a transmission power of an IR light beam corresponding to the far-channel IR detection is greater than a transmission power of an IR light beam corresponding to the near-channel IR detection, the screen ON-and-OFF state control method being characterized in that the step of, during the distance detection through the far-channel IR detection, when the timing start condition for the near-channel IR detection has been met, the interrupting, by the processor, the far-channel IR detection and enabling the near-channel IR detection for the distance detection comprises the steps of: receiving a timing signal from a timer, the timing signal being transmitted by the timer at a predetermined frequency; upon the receipt of the timing signal, determining an ON/OFF state of the screen of the mobile terminal (400; 500); and when the screen of the mobile terminal (400; 500) is in the ON state, interrupting the far-channel IR detection, and enabling the near-channel IR detection for the distance detection. a step of, during a distance detection through a far-channel Infrared - IR detection, when a timing start condition for a near-channel IR detection has been met, interrupting, by the processor, the far-channel IR detection, and enabling the near-channel IR detection for the distance detection; and a step of controlling, by the processor, ON and OFF states of a screen of the mobile terminal (400; 500) in accordance with a distance detection result of the near-channel IR detection, wherein a transmission power of an IR light beam corresponding to the far-channel IR detection is greater than a transmission power of an IR light beam corresponding to the near-channel IR detection, the screen ON-and-OFF state control method being characterized in that the step of, during the distance detection through the far-channel IR detection, when the timing start condition for the near-channel IR detection has been met, the interrupting, by the processor, the far-channel IR detection and enabling the near-channel IR detection for the distance detection comprises the steps of: receiving a timing signal from a timer, the timing signal being transmitted by the timer at a predetermined frequency; upon the receipt of the timing signal, determining an ON/OFF state of the screen of the mobile terminal (400; 500); and when the screen of the mobile terminal (400; 500) is in the ON state, interrupting the far-channel IR detection, and enabling the near-channel IR detection for the distance detection. receiving a timing signal from a timer, the timing signal being transmitted by the timer at a predetermined frequency; upon the receipt of the timing signal, determining an ON/OFF state of the screen of the mobile terminal (400; 500); and when the screen of the mobile terminal (400; 500) is in the ON state, interrupting the far-channel IR detection, and enabling the near-channel IR detection for the distance detection.