A mobile terminal, comprising a processor, an infrared acquisition device connected with the processor, a memory, wherein the infrared acquisition device comprises an infrared camera and a supplementary infrared light device, the supplementary infrared light device comprises a supplementary infrared light lamp and wherein the infrared acquisition device is configured to acquire an iris image of a current user; the memory is configured to store an iris image template; the supplementary infrared light lamp is configured to emit visible red light and infrared light; and the processor is configured to execute the following operations: obtaining a current ambient brightness value of the mobile terminal, in response to obtaining of the current ambient brightness value being greater than or equal to a preset brightness threshold value, determining that a target working mode of the infrared acquisition device is a first working mode; and in response to obtaining of the current ambient brightness value being lower than the preset brightness threshold value, determining that the target working mode of the infrared acquisition device is a second working mode, and acquiring the iris image of the current user in the target working mode via the infrared acquisition device; characterised in that: the supplementary infrared light device further comprises a light filter configured to filter the visible red light; wherein in the first working mode, the visible red light emitted by the supplementary infrared light lamp is filtered out by the light filter; and in the second working mode, neither the visible red light nor the infrared light, emitted by the supplementary infrared light lamp is filtered by the light filter. the infrared acquisition device is configured to acquire an iris image of a current user; the memory is configured to store an iris image template; the supplementary infrared light lamp is configured to emit visible red light and infrared light; and the processor is configured to execute the following operations: obtaining a current ambient brightness value of the mobile terminal, in response to obtaining of the current ambient brightness value being greater than or equal to a preset brightness threshold value, determining that a target working mode of the infrared acquisition device is a first working mode; and in response to obtaining of the current ambient brightness value being lower than the preset brightness threshold value, determining that the target working mode of the infrared acquisition device is a second working mode, and acquiring the iris image of the current user in the target working mode via the infrared acquisition device; obtaining a current ambient brightness value of the mobile terminal, in response to obtaining of the current ambient brightness value being greater than or equal to a preset brightness threshold value, determining that a target working mode of the infrared acquisition device is a first working mode; and in response to obtaining of the current ambient brightness value being lower than the preset brightness threshold value, determining that the target working mode of the infrared acquisition device is a second working mode, and acquiring the iris image of the current user in the target working mode via the infrared acquisition device; characterised in that: the supplementary infrared light device further comprises a light filter configured to filter the visible red light; wherein in the first working mode, the visible red light emitted by the supplementary infrared light lamp is filtered out by the light filter; and in the second working mode, neither the visible red light nor the infrared light, emitted by the supplementary infrared light lamp is filtered by the light filter. the supplementary infrared light device further comprises a light filter configured to filter the visible red light; wherein in the first working mode, the visible red light emitted by the supplementary infrared light lamp is filtered out by the light filter; and in the second working mode, neither the visible red light nor the infrared light, emitted by the supplementary infrared light lamp is filtered by the light filter.