A practical bandgap reference voltage source is designed with quick start and high stability. It selects 110?nm CMOS(Complementary Metal Oxide Semiconductor) device technology and simulation software of Cadence. The simulation results indicate that under room temperature, the output voltage is 1.2 V under 3.3 V power supply; the temperature drift coefficient is 33 ppm/℃ between -40?℃-85 ℃; it takes 0.5?μs to start the circuit; and the power consumption is 0.967?mW; Power Supply Rejection Ratio(PSRR) reaches -61?dB in the range of low frequency; the layout covers an area of 50?μm×180?μm. Because its simple structure and being easy to be integrated, the circuit can be applied to DAC(Digital to Analog Converter) with high speed and high precision.