A head-up display, comprising a laser light source , a micro-electro-mechanical system , a diffuser film , and an apparatus for detecting a shift of the diffuser film , wherein the apparatus comprises a power supply , a conductive module , and a detection module ; a relatively fixed position relationship exists between the conductive module and the diffuser film ; when the diffuser film is in a first position, the conductive module is connected to the power supply to form a closed loop; when the diffuser film is shifted from the first position to a second position, a position of the conductive module changes to make the closed loop open; a shift distance from the second position to the first position is greater than a preset distance; the detection module is configured to detect that the closed loop is opened; the diffuser film is fastened to a bearer module ; the conductive module is connected to the bearer module ; the bearer module comprises a first frame ; the diffuser film is in the first frame , and the diffuser film is adhered to the first frame ; the conductive module is fastened to the first frame ; the bearer module further comprises a foot ; the foot is connected to the first frame , and is configured to support the first frame ; the conductive module is disposed below the foot and connected to the foot ; when the diffuser film is in the first position, laser light emitted by the laser light source is scanned by the micro-electro-mechanical system and incident on the diffuser film ; and when the diffuser film is in the second position, the diffuser film deviates from an optical path of the laser light scanned by the micro-electro-mechanical system . the apparatus comprises a power supply , a conductive module , and a detection module ; a relatively fixed position relationship exists between the conductive module and the diffuser film ; when the diffuser film is in a first position, the conductive module is connected to the power supply to form a closed loop; when the diffuser film is shifted from the first position to a second position, a position of the conductive module changes to make the closed loop open; a shift distance from the second position to the first position is greater than a preset distance; the detection module is configured to detect that the closed loop is opened; the diffuser film is fastened to a bearer module ; the conductive module is connected to the bearer module ; the bearer module comprises a first frame ; the diffuser film is in the first frame , and the diffuser film is adhered to the first frame ; the conductive module is fastened to the first frame ; the bearer module further comprises a foot ; the foot is connected to the first frame , and is configured to support the first frame ; the conductive module is disposed below the foot and connected to the foot ; when the diffuser film is in the first position, laser light emitted by the laser light source is scanned by the micro-electro-mechanical system and incident on the diffuser film ; and when the diffuser film is in the second position, the diffuser film deviates from an optical path of the laser light scanned by the micro-electro-mechanical system . <EOS>