[Objective] The study aims to explore the effects of Fusarium oxysporum infection on physiological and biochemical indices of tomato resistant rootstock grafted seedlings, and to provide theoretical basis for revealing the mechanism of grafting in improving tomato resistance to Fusarium wilt. [Methods] Tomato disease-resistant material ‘FR’ was used as rootstock and the susceptible material ‘AC’ was used as scion. Grafting was conducted onto both resistant rootstocks and self-rooted plants of susceptible material. Pathogenesis, photosynthesis, antioxidant enzyme activity, hormone content and related gene expression were measured in both two types of grafted plants following infection with F. oxysporum. [Results] Compared with self-rooted plants, the disease index and incidence of Fusarium wilt disease of tomato grafted plants were significantly reduced by 95.6% and 90.7%, respectively. After F. oxysporum infection, grafted plants exhibited significantly higher photosynthetic parameters, such as net photosynthetic rate, stomatal conductance, transpiration rate and maximum photochemical efficiency, as well as increased jasmonic acid content and enhanced expression of genes in the JA signaling suppressor pathway, compared to self-rooted plants. The activities of SOD, POD, CAT, and APX in grafted plants were lower than those in self-rooted plants, while salicylic acid and aminocyclopropane-1-carboxylate levels showed no significant differences. However, the expression of genes in the SA and ET signaling pathways, was higher in grafted plants than in self-rooted plants. [Conclusion] Grafting onto resistant rootstocks significantly enhances tomato resistance to Fusarium wilt. This increased resistance is primarily achieved through the improvement of leaf photosynthetic efficiency, regulation of antioxidant enzyme activity, and activation of systemic resistance via signaling pathways.