This invention is one kind of automatic control vehicles head lamp height control device, this control device examines including a state of roads knows the unit as well as moves the unit identically, this state of roads examines knows the unit to include an acceleration sensory element (G Sensor) to connect a microprocessor, this acceleration sensory element may send in it with the gravitational field between relative angle this microprocessor to obtain vehicles' angle of tilt, leaves the plant based on the vehicles when front light's laws and regulations terminal altitude takes the datum again, the coordinate actuation should send moves the unit adjustment front light, front maintains the illumination zone, enhances the night driving security.