Objective: To investigate the in vivo biocompatibility and efficacy of salvianolic acid B (SAB) -sodium alginate-gelatin skin scaffold prepared by 3D bioprinting technology in the treatment of diabetic wounds. Methods: The 0, 0.5, 1.0 and 1.5 wt% of bioinks were prepared according to the percentage of SAB in the total weight of sodium alginate and gelatin (wt%). Skin scaffolds with different type were produced by biological 3D printing technology. The microstructure was observed by scanning electron microscopy, and the concentration of SAB in vitro was determined by High-performance liquid chromatography. The skin scaffold was used in the treatment of ulcer of rats with type 2 diabetes milltus, and the healing and exudation of the ulcer were observed and photo-recorded on the 7th and 14th day. Meanwhile, the wound tissue was taken for HE, Masson, reactive oxygen species (ROS) staining, and the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT), and malondialdehyde (MDA) were detected. Results: All the skin scaffolds showed a mesh-like three-dimensional structure with uniform pore distribution. The cumulative release of the drug increases gradually over time. General observations: wounds healed well in each group, 1% groups healing better than other groups. On days 7 and 14, ROS level in 1.0%SAB group was lower than that in other groups (P<0.05). On day 7, the levels of SOD, GSH-PX and CAT in 1.0%SAB group were higher than those in other groups (P<0.005), MDA level was lower than that of the control group, vaseline gauze group and 0%SAB group. On day 14, the levels of SOD, GSH-PX and CAT in 1.0%SAB group were higher than those in control group, vasolin gauze group and 0%SAB group (P<0.005), MDA level was lower than that in the control group and vaseline gauze group (P<0.05). HE staining: the wounds was well repaired of each group, and more new tissue was formed in the 1.0%SAB group. Masson staining: on days 7 and 14, collagen deposition in 0.5, 1.0, 1.5% groups was more than that in other groups (P<0.05). Conclusion: The 1.0% SAB-alginate-gelatin skin scaffold can not only inhibit the production of ROS and up-regulate the expression of various antioxidant enzymes, thereby inhibiting oxidative stress response in wound tissue, but also promote the deposition of collagen, and ultimately promote the repair of diabetic ulcer wound.