Based on the transfer matrix method and the principle of light localization, the optical bi stability (OB) changing with magnetic field strength, incident angle and dielectric layer are investigated in an one-dimensional antiferromagnetic photonic crystal near the resonant frequencies. We find that the OBs can be observed near the two resonant frequencies at a smaller incident angle, but they disappear near the higher resonant frequencies at a bigger incident angle when the magnetic field strength is 1.0 kG. However, once the external magnetic field strength increases up to 2.0 kG, the lost OB will be induced due to the the two resonant frequencies shifting towards two sides. In addition, the dielectric layers also have a greater influence on OB near the lower resonant frequencies at a smaller incident angle.