An anti-TID radiation bandgap voltage reference was designed in a standard CMOS IC process. The intrinsic weakness of traditional bandgap framework in radiation situation was analyzed. The resistance of the bandgap voltage reference to total dose radiation was improved by taking of advantages of the characteristics that the diode positive guide voltage was less affected by current. The bandgap voltage reference consisted of a startup circuit, a BGR core circuit and a self-bias circuit. The bandgap voltage reference was integrated in a 12 bit 100 kS/s sampling rate A/D converter as a unit, and the ADC was fabricated and tested. The results showed that the output voltage of the reference changed little after the total dose radiation test. Under the -55 ℃~125 ℃ temperature range, the temperature drift coefficient was 1.53×10-5/℃ before total dose radiation, and it was 1.71×10-5/℃ after total dose radiation.