A theoretical study on Sb-doped SnO2 was carried out using a plane wave pesudopotential schene density functional theory (DFT) at the generalized gradient approximation (GGA) level. Stability and conductivity analyses were performed based on the formation energy of doping and the electronic structures. Results show that the SnO2 lattice constants expand into a distorted rutile structure as the antimony content increases. The formation energy of doping shows little change as the doping ratio changes and it has a minimum value of 5.08 eV at a doping ratio of 0.083. This suggests that the Sn0.917Sb0.083O2 solid solution has the highest stability. Density of state (DOS) calculations showed that a Sb 5s distribution of electronic states exists from the Fermi level to the lowest conduction band after doping with antimony. In addition, 19 electrons were present in the lowest conduction band after doping compared to 4 electrons before doping. This results in the increased conductivity of the solid solution. At a doping ratio of 0.063, the Sn0.937Sb0.063O2 solid solution had the strongest conductivity. These results provide a theoretical basis for the development and application of Sn1-xSbxO2 solid solution electrodes.