Abstract: In short baseline reactor antineutrino experiment, the distance between the detector and the reactor is relatively short, the impact of reactor geometry effects on the neutrino spectrum and flux may not be neglected. In this paper, a volume neutrino source model and a point neutrino source model is established based on the structure of the EPR reactor core. The impact of the geometric effect to the antineutrino spectrum and flux in short baseline neutrino experiments is studied, the impact of the uncertainty of the power distribution in the core to the expected neutrino flux in the point model is also discussed. Because of the geometry effect of the core, the point source model can lead to a reduction in the expected neutrino event rate by approximately 0.08% to 0.40%, and the impact of the geometry effects on the shape of neutrino spectrum is on the order of 10⁻⁶. In a short baseline reactor antineutrino experiment, a point neutrino source model based on the geometric center of the reactor core can be used to calculate the neutrino flux, the uncertainty introduced by statistical and systematic uncertainties can be neglected in this model.