A light sensor to be installed behind a display screen, the light sensor comprising at least one light sensor submodule, wherein each light sensor submodule comprises a first light detector, a second light detector, a first linear polarizer, a second linear polarizer, a first phase delay film, and a second phase delay film, wherein the first light detector and the second light detector are disposed adjacently to each other; the first linear polarizer is located above the first light detector; the second linear polarizer is located above the second light detector; the first phase delay film is located above the first linear polarizer; the second phase delay film is located above the second linear polarizer; and the first light detector is configured to obtain light intensity of first hybrid light resulting when hybrid light has passed through the first phase delay film and the first linear polarizer, and the second light detector is configured to obtain light intensity of second hybrid light resulting when the hybrid light has passed through the second phase delay film and the second linear polarizer, wherein the hybrid light comprises first light and second light, and after the hybrid light passes through the second linear polarizer, the first light is filtered out; wherein a fast axis direction of the first phase delay film is the same as a fast axis direction of the second phase delay film, or a slow axis direction of the first phase delay film is the same as a slow axis direction of the second phase delay film; and a polarization direction of the first linear polarizer is the same as a polarization direction of first linearly polarized light resulting when the first light has passed through the first phase delay film, and a polarization direction of the first light is orthogonal to a polarization direction of the second linear polarizer; wherein the light sensor further comprises a processor, and the processor is configured to: obtain total intensity of the first light and the second light that is detected by the first light detector, and light intensity, detected by the second light detector, of the second light, and output a difference between the light intensity detected by the first light detector and the light intensity detected by the second light detector; wherein the first light is circularly polarized light resulting when ambient light has passed through a display screen disposed with a circular polarizer; and the second light is light emitted by a light emitting component of the display screen; wherein the first linear polarizer and the second linear polarizer are disposed in a single plane. the first light detector and the second light detector are disposed adjacently to each other; the first linear polarizer is located above the first light detector; the second linear polarizer is located above the second light detector; the first phase delay film is located above the first linear polarizer; the second phase delay film is located above the second linear polarizer; and the first light detector is configured to obtain light intensity of first hybrid light resulting when hybrid light has passed through the first phase delay film and the first linear polarizer, and the second light detector is configured to obtain light intensity of second hybrid light resulting when the hybrid light has passed through the second phase delay film and the second linear polarizer, wherein the hybrid light comprises first light and second light, and after the hybrid light passes through the second linear polarizer, the first light is filtered out; wherein a fast axis direction of the first phase delay film is the same as a fast axis direction of the second phase delay film, or a slow axis direction of the first phase delay film is the same as a slow axis direction of the second phase delay film; and a polarization direction of the first linear polarizer is the same as a polarization direction of first linearly polarized light resulting when the first light has passed through the first phase delay film, and a polarization direction of the first light is orthogonal to a polarization direction of the second linear polarizer; wherein the light sensor further comprises a processor, and the processor is configured to: obtain total intensity of the first light and the second light that is detected by the first light detector, and light intensity, detected by the second light detector, of the second light, and output a difference between the light intensity detected by the first light detector and the light intensity detected by the second light detector; wherein the first light is circularly polarized light resulting when ambient light has passed through a display screen disposed with a circular polarizer; and the second light is light emitted by a light emitting component of the display screen; wherein the first linear polarizer and the second linear polarizer are disposed in a single plane.