Abstract: Tobacco extract is an important type of tobacco flavoring and fragrance, but the macromolecular impurities such as pectin it contains can have an adverse effect on the taste quality. To reduce pectin content and achieve quality improvement and aroma enhancement, in this study, gel beads with sodium alginate (SA) - gelatin (GE) composite carriers were constructed, pectinase was immobilized. Combined with single-factor experiments and response surface optimization techniques, the preparation process was systematically optimized to evaluate its application effect in tobacco extracts. The results showed that: 1) When the composite gel beads prepared with a SA:GE mass ratio of 1:1 and a total concentration of 4%, the immobilized pectinase exhibited a relatively high enzyme loading capacity, and the highest activity recovery rate was achieved. Under the conditions of an initial pectinase concentration of 3%, an immobilization temperature of 33°C, an immobilization pH of 3.6, and an immobilization time of 3.5 h, the enzyme activity recovery rate reached 46.99%. 2) Compared with free pectinase, the immobilized pectinase maintained a relatively high relative activity under conditions of 50% ethanol and 50% propylene glycol, respectively. It exhibited superior stability across a pH range of 1 to 7. At 80°C, the immobilized enzyme retained 63.47% of its initial activity. Furthermore, after five repeated cycles of use, its activity remained above 40%. 3) After adding immobilized-pectinase-treated Yuyan tobacco extract to blank cigarettes, the cigarette samples exhibited enhanced aroma, increased aroma richness, reduced off-notes, and significantly diminished irritation. This study confirms the feasibility of using SA-GE composite gel immobilization technology to improve the quality of tobacco extracts, providing a new pathway for enhancing the quality and efficacy of tobacco extracts.