AbstractMaltitol, a natural compound, offers a potentially eco‐friendly alternative to conventional auxiliary thermal stabilizers. Its auxiliary stabilization effect was studied by discoloration tests, Congo red tests, thermogravimetric analysis, and UV–visible spectroscopy. Additionally, x‐ray photoelectron spectroscopy and discoloration tests were used to study the stabilizing mechanisms of maltitol. Compared to dipentaerythritol, commonly used in the PVC industry, maltitol as an auxiliary stabilizer exhibits better improvement in thermal stability. This improvement is related to its melting point, ability to complex with zinc chloride, and content of hydroxyl groups. Furthermore, the addition of maltitol in PVC not only maintains good transparency of PVC basically unchanged but also improves the mechanical properties. Maltitol, as a natural, eco‐friendly, and efficient auxiliary thermal stabilizer, exhibits a promising application prospect in PVC materials.