Abstract: SrTiO₃ capacitor-varistor multifunctional ceramics are prepared by single- firing process and the investigation has been carried out mainly aiming at the influences of SiO₂-TiO₂-Al₂O₃ system sintering aid on the structure and multifunctional properties of the ceramics. The results indicate that the sintering aid with moderate composition promotes the sintering and improves the structure of the ceramics, while the multifunctional properties of the ceramics are optimized relevantly. The optimized composition of the sintering aid is ascertained to be 0.5wt%SiO₂-0.2wt%TiO₂-0.05wt%Al₂O₃ based on the investigations in this paper.