The invention discloses a fog lamp for prolonging a travel safe sight distance and an arrangement method and relates to the technical field of highway lighting. The fog lamp is suitable for lighting alow-visibility road segment and comprises a lamp box, high-color-temperature LED beads, condensing lenses, a transparent window and a lampshade, wherein the lamp box is fixedly arranged on a guardrail; the high-color-temperature LED beads are arranged inside the lamp box; each condensing lens is arranged inside the lamp box and is connected with the corresponding LED bead; the transparent windowis arranged in the outer portion of the lamp box, and the periphery of the transparent window is detachably connected with the lamp box; and the lampshade is arranged at the top of the lamp box. According to the fog lamp, light source characteristics and light distribution parameters which are beneficial for visual recognition in a low-visibility environment are adopted, the visual recognition ability of a driver or a pedestrian can be improved, the driver can clearly see far obstacles on a foggy day and meanwhile can see travel tracks of front vehicles so as to take actions to avoid the obstacles and the vehicles in time, the occurrence of a traffic accident is avoided, and the life health of the driver and the pedestrian is effectively ensured.