The invention relates to an LED light-emitting system applied to a vehicle and aims to solve the problem that power cannot be supplied to LED lamps continuously in the prior art. The system comprises LED lamp strings, LED lamp driving circuits and permanent magnets, wherein the LED lamp strings and the LED lamp driving circuits are mounted on wheel hubs separately; the permanent magnets are mounted on butterfly brake calipers of the vehicle; the LED lamp driving circuits comprise sensing bodies, rectifying circuits connected to the output of the sensing bodies as well as capacitors C connected to the output of the rectifying circuits and used for storing power, and the LED lamp strings are electrically connected to two ends of the capacitors C. According to the system, working voltage is provided for LED lamps through matching of the permanent magnets mounted on brake linings and the sensing bodies mounted on the hubs, and the problem that the power cannot be supplied to the LED lamps continuously in the prior art is solved.