Deficiencies in repair cells and infection are two of the main factors that can hinder the process of wound healing. In the present study, we investigated the ability of human beta-defensin-2 (hBD2) genetically modified dermal multipotent stem cells (dMSCs) to accelerate the healing irradiated wounds complicated by infections. An hBD2 adenovirus expression vector (Adv-hBD2) was firstly constructed and used to infect dMSCs. The antibacterial activity of the supernatant was determined by Kirby-Bauer method and macrodilution broth assay. Time to complete wound healing, residual percentage of wound area, and the number of bacteria under the scar were measured to assess the effects of Adv-hBD2-infected dMSC transplantation on the healing of irradiated wounds complicated by Pseudomonas aeruginosa infection. Results showed that the supernatant from Adv-hBD2-infected dMSCs had obvious antibacterial effects. Transplantation of Adv-hBD2-infected dMSCs killed bacteria in the wound. The complete wound healing time was 19.8 ± 0.45 days, which was significantly shorter than in the control groups (P < 0.05). From 14 days after transplantation, the residual wound area was smaller in the experimental group than in the control groups (P < 0.05). In conclusion, we found that transplantation of hBD2 genetically modified dMSCs accelerated the healing of wounds complicated by P. aeruginosa infection in whole body irradiated rats.