A temperature and illumination adjusting system, comprising: a temperature and illumination adjusting device, comprising: a central processing unit, adapted to receive an illumination value, L, and a color-temperature value, CCT, and adapted to generate a first duty cycle value of pulse width modulation PWM1 and a second duty cycle value of pulse width modulation PWM2 according to a first formula and a second formula; a memory unit, adapted to store the first formula and the second formula. a communication unit, adapted to output PWM1 and PWM2; and a lamp device, comprising: a lamp communication unit, adapted to receive PWM1 and PWM2; a first light module; a second light module; a first PWM driving unit, adapted to receive PWM1 from the lamp communication unit and to drive the first light module by pulse width modulation having a duty cycle according to PWM1 and a second PWM driving unit, adapted to receive PWM2 from the lamp communication unit and to drive the second light module by pulse width modulation having a duty cycle according to PWM2. wherein the outputs of the first light module and the second light module have different color temperatures, characterized in that the first formula indicates the correlation between PWM1, PWM2 and the illumination value L; the second formula indicates the correlation between PWM1, PWM2 and the color-temperature value CCT; whein the first formula is PWM 2 = A L + B L * PWM 1, and wherein A L = a 1 + a 2 L, B L = b 1 + b 2 L, and wherein A =a 1 +a 2 L, B =b 1 +b 2 L, and a 1, a 2, b 1, b 2 are constants; and the second formula is PWM2/PWM1=c 1 *e -CCT/c2 +c 3. and wherein c1, c2, c3 are constants and e is a mathematical constant. a temperature and illumination adjusting device, comprising: a central processing unit, adapted to receive an illumination value, L, and a color-temperature value, CCT, and adapted to generate a first duty cycle value of pulse width modulation PWM1 and a second duty cycle value of pulse width modulation PWM2 according to a first formula and a second formula; a central processing unit, adapted to receive an illumination value, L, and a color-temperature value, CCT, and adapted to generate a first duty cycle value of pulse width modulation PWM1 and a second duty cycle value of pulse width modulation PWM2 according to a first formula and a second formula; a memory unit, adapted to store the first formula and the second formula. a communication unit, adapted to output PWM1 and PWM2; and a lamp device, comprising: a lamp communication unit, adapted to receive PWM1 and PWM2; a first light module; a second light module; a first PWM driving unit, adapted to receive PWM1 from the lamp communication unit and to drive the first light module by pulse width modulation having a duty cycle according to PWM1 and a second PWM driving unit, adapted to receive PWM2 from the lamp communication unit and to drive the second light module by pulse width modulation having a duty cycle according to PWM2. wherein the outputs of the first light module and the second light module have different color temperatures, characterized in that the first formula indicates the correlation between PWM1, PWM2 and the illumination value L; the second formula indicates the correlation between PWM1, PWM2 and the color-temperature value CCT; whein the first formula is PWM 2 = A L + B L * PWM 1, and wherein A L = a 1 + a 2 L, B L = b 1 + b 2 L, and wherein A =a 1 +a 2 L, B =b 1 +b 2 L, and a 1, a 2, b 1, b 2 are constants; and the second formula is PWM2/PWM1=c 1 *e -CCT/c2 +c 3. and wherein c1, c2, c3 are constants and e is a mathematical constant. a lamp communication unit, adapted to receive PWM1 and PWM2; a first light module; a second light module; a first PWM driving unit, adapted to receive PWM1 from the lamp communication unit and to drive the first light module by pulse width modulation having a duty cycle according to PWM1 and a second PWM driving unit, adapted to receive PWM2 from the lamp communication unit and to drive the second light module by pulse width modulation having a duty cycle according to PWM2.