A mobile terminal, comprising: a face information collecting device, configured to collect a face image; a memory, configured to prestore a face template; and a processor, configured to carry out following actions, comprising: when detecting a trigger event of lighting a screen of the mobile terminal, obtaining an event identifier of the trigger event; when detecting that the event identifier matches a pre-stored event identifier, turning on the face information collecting device and lighting the screen of the mobile terminal, wherein turning on the face information collecting device and lighting the screen of the mobile terminal comprises: turning on the face information collecting device and lighting the screen of the mobile terminal in parallel; detecting whether a switch for launching a preview interface is in an open state; when detecting that the switch is in the open state, displaying the preview interface on a display interface of the mobile terminal, the preview interface being configured to display the face image collected by the face information collecting device; and when detecting that the face image collected by the face information collecting device matches the pre-stored face template, performing an unlocking operation. a face information collecting device, configured to collect a face image; a memory, configured to prestore a face template; and a processor, configured to carry out following actions, comprising: when detecting a trigger event of lighting a screen of the mobile terminal, obtaining an event identifier of the trigger event; when detecting that the event identifier matches a pre-stored event identifier, turning on the face information collecting device and lighting the screen of the mobile terminal, wherein turning on the face information collecting device and lighting the screen of the mobile terminal comprises: turning on the face information collecting device and lighting the screen of the mobile terminal in parallel; detecting whether a switch for launching a preview interface is in an open state; when detecting that the switch is in the open state, displaying the preview interface on a display interface of the mobile terminal, the preview interface being configured to display the face image collected by the face information collecting device; and when detecting that the face image collected by the face information collecting device matches the pre-stored face template, performing an unlocking operation. when detecting a trigger event of lighting a screen of the mobile terminal, obtaining an event identifier of the trigger event; when detecting that the event identifier matches a pre-stored event identifier, turning on the face information collecting device and lighting the screen of the mobile terminal, wherein turning on the face information collecting device and lighting the screen of the mobile terminal comprises: turning on the face information collecting device and lighting the screen of the mobile terminal in parallel; detecting whether a switch for launching a preview interface is in an open state; when detecting that the switch is in the open state, displaying the preview interface on a display interface of the mobile terminal, the preview interface being configured to display the face image collected by the face information collecting device; and when detecting that the face image collected by the face information collecting device matches the pre-stored face template, performing an unlocking operation.