A full-screen optical component, applied to an electronic device, wherein the electronic device comprises a display screen, the full-screen optical component comprises a backlight module, an active light sensor, and a dimmer configured to adjust an angle of light emitted by the active light sensor, and the display screen and the active light sensor are located on two opposite sides of the backlight module; the backlight module comprises a first prism film and a second prism film stacked on the first prism film, the first prism film comprises several first prisms disposed in parallel, the second prism film comprises several second prisms disposed in parallel, and a long axis of the first prism and a long axis of the second prism are perpendicular to each other; and the first prism comprises a first in-light surface and a first out-light surface, the second prism comprises a second in-light surface and a second out-light surface, and a display surface of the display screen, the first in-light surface, and the second in-light surface are disposed in parallel; the active light sensor comprises a sensor and a light emitter, and the sensor is configured to sense a reflected light signal of light emitted by the light emitter; and the dimmer is configured to direct the light emitted by the light emitter to the first in-light surface at a first incident angle that is inclined relative to a vertical direction, so that the light is then emitted from the first out-light surface after being refracted by the first prism, enters the second in-light surface at a second incident angle that is inclined relative to the vertical direction, and is emitted from the second out-light surface after being refracted by the second prism, so that the light passes through the display screen at a vertical angle. the backlight module comprises a first prism film and a second prism film stacked on the first prism film, the first prism film comprises several first prisms disposed in parallel, the second prism film comprises several second prisms disposed in parallel, and a long axis of the first prism and a long axis of the second prism are perpendicular to each other; and the first prism comprises a first in-light surface and a first out-light surface, the second prism comprises a second in-light surface and a second out-light surface, and a display surface of the display screen, the first in-light surface, and the second in-light surface are disposed in parallel; the active light sensor comprises a sensor and a light emitter, and the sensor is configured to sense a reflected light signal of light emitted by the light emitter; and the dimmer is configured to direct the light emitted by the light emitter to the first in-light surface at a first incident angle that is inclined relative to a vertical direction, so that the light is then emitted from the first out-light surface after being refracted by the first prism, enters the second in-light surface at a second incident angle that is inclined relative to the vertical direction, and is emitted from the second out-light surface after being refracted by the second prism, so that the light passes through the display screen at a vertical angle.