An intelligent light device for a vehicle comprising a light body, a light-controlling unit, a light-emitting unit and a condensing lens; wherein the light body has a reflective cup defined at a front portion thereof, the reflective cup concaved toward one end of the light body, an opening is defined at one end of the reflective cup, the condensing lens is defined at the opening of the reflective cup, the light-controlling unit is connected on the reflective cup of the light body, the light-emitting unit is defined on an inner wall of the reflective cup and faces toward the condensing lens, the light-emitting unit is adapted to emit, at a second illumination level, a light beam which is configured to be refracted through the condensing lens and to form a light projection region having a third illumination level, the light-controlling unit is adapted to face toward the light projection region; wherein the light-controlling unit is adapted to sense a first illumination level of a surrounding area of the light projection region, the intelligent light device being characterized in that the light-controlling unit has a micro control unit, a pulse width modulation unit, and a buffering unit, wherein the micro control unit has a preset illumination level which is a desired value for the third illumination level, and is adapted to: receive a signal of the first illumination level, compare the signal with the preset illumination level and generate a difference value between the preset illumination level and the first illumination level; transmit the difference value as one command to the pulse width modulation unit; wherein the pulse width modulation unit is adapted to adjust the second illumination level of the light-emitting unit according to the command from the micro control unit so as to achieve the third illumination level of the light projection region by increasing or decreasing the second illumination level; wherein the buffering unit has a preset buffering time, wherein the micro control unit is further adapted to: when the first illumination level sensed via the light-controlling unit changes within one time interval which is shorter than the preset buffering time of the buffering unit, generate a command so as to stop, via the pulse width modulation unit, the light-emitting unit from adjusting the second illumination level, when the first illumination level sensed via the light-controlling unit changes within another time interval which is longer than the preset buffering time of the buffering unit, integrate, together with the buffering unit, the data of said another time interval and the first illumination level so as to generate said difference value as the command for transmission to the pulse width modulation unit so that the second illumination level of the light-emitting unit is adjusted so as to achieve the third illumination level of the light projection region. receive a signal of the first illumination level, compare the signal with the preset illumination level and generate a difference value between the preset illumination level and the first illumination level; transmit the difference value as one command to the pulse width modulation unit; when the first illumination level sensed via the light-controlling unit changes within one time interval which is shorter than the preset buffering time of the buffering unit, generate a command so as to stop, via the pulse width modulation unit, the light-emitting unit from adjusting the second illumination level, when the first illumination level sensed via the light-controlling unit changes within another time interval which is longer than the preset buffering time of the buffering unit, integrate, together with the buffering unit, the data of said another time interval and the first illumination level so as to generate said difference value as the command for transmission to the pulse width modulation unit so that the second illumination level of the light-emitting unit is adjusted so as to achieve the third illumination level of the light projection region.