In order to investigate the dose rate effect and the radiation response of the voltage comparator, a group of bipolar voltage comparators are irradiated by 60Co at high-and low-dose rates under different bias conditions. The results show that many of the parameters for the voltage comparator subjected to ionization radiation, such as power current, input bias current, input offset voltage, and output voltage, are degraded to a certain extent; the irradiation response of the voltage comparator is severely affected by bias condition. What is more, the same type of circuits manufactured from different companies exhibit different dose rate effects; the reasons for the degradation are discussed by analyzing the experiment results. The mechanism for the formation of dose rate effect is also analyzed from the annealing characteristics. The results obtained in this paper are not only useful for the applications of the radiation hardness device, but also helpful for its design.