The blue and yellow tangent laser headlight is a kind of car headlights. The blue tangent line indicates that the boundary line of the beam irradiated by the laser headlamp on the road surface is blue. Blue light has high energy and short wavelength, so the blue tangent can provide brighter and clearer lighting effect, which is helpful to improve the visibility of driving at night. The yellow tangent line indicates that the boundary line of the light beam irradiated by the laser headlamp on the road surface appears yellow. Yellow light has low energy and long wavelength, so the yellow tangent is relatively dark. The yellow tangent is considered to be friendly to other vehicles and will not cause too much stimulation and interference.