The utility model discloses an LED guardrail lamp with light polarizing and dimming functions. The LED guardrail lamp comprises steel tube supports, a steel tube, outer covers and LED unit modules. The two adjacent steel tube supports are used for supporting and fixing the steel tube, the outer covers and the steel tube are structurally matched to form a cavity, and the LED unit modules are arranged in the cavity. The LED unit modules comprise PC surface covers, aluminum sectional materials, silica gel rings and light polarizing lenses. The PC surface covers are structurally matched with the aluminum sectional materials to form a cavity for containing an LED light source, PCB circuits and the silica gel rings are arranged on the aluminum sectional materials, LED lamp beads are electrically connected with the PCB circuits and the light polarizing lenses are arranged on the LED lamp beads in a covering mode. Compared with the prior art, the LED guardrail lamp with the light polarizing and dimming functions has the advantages that light polarizing and anti-dazzle design is carried out, the light brightness is controlled according to the road conditions at night, therefore, driving safety accidents are reduced, and the defects in the prior art are effectively overcome. The LED guardrail lamp with the light polarizing and dimming functions is simple in structure and environmentally friendly, saves energy and has good practicability, and industrialization is easy to realize.