ObjectiveTo establish a stable and high reproducibility rat model of deep seconddegree scald and wound infection for the study of repair and treatment of scald and wound infection.Methods40 SD rats were randomly divided into 5 groups, selfmade scald instrument (steam temperature 94℃) was used to produce scald on rats’ skin for 4, 6, 8, 10, and 12 seconds (identical wound at two sides of the spine of each rat), histological changes on wound was observed 24 hours after injury, the best duration for forming deep seconddegree scald was analyzed. Another 30 SD rats were randomly divided into 3 groups, with 10 rats in each group, deep seconddegree scald was formed with the best injury time, 0.3 mL liquid containing 1×107 CFU/mL, 1×108 CFU/ml, and 1×109 CFU/mL Pseudomonas aeruginosa (P. aeruginosa) was respectively inoculated to the wound on one side, while the wound on the other side were inoculated with the same volume of normal saline as control, general condition of rats wound was observed 24 hours after inoculation, HE staining was used to stain the wound and observe inflammatory reaction, the number of bacteria under schar was detected after 1, 2, 4, 7, and 14 days of inoculation, wound healing time was recorded.Results(1) Histopathological findings showed that scald for 8 seconds was the best time for forming deep seconddegree wound. (2) Inoculation of 1×108 CFU/mL and 1×109 CFU/mL bacteria to rat deep seconddegree scald had obvious inflammatory cell infiltration, inflammatory infiltration under the scab of the latter was more obvious. The subeschar bacterial count was 1×105 CFU/g within 14 days after inoculation of 1×109 CFU/mL bacteria to scald wound, and bacteria count showed a rising trend over time. Wound healing time of rats was significantly longer than that of the saline control group(［21.4±2.4］d vs ［18.4±1.7］ d, t=2.72，P＜0.05）.ConclusionTemperature at 94℃ and scald time for 8 seconds is the optimal time for forming deep seconddegree scald; inoculation with P. aeruginosa at a concentration of 1×109 CFU/mL to scald wound can establish a deep seconddegree scald and infection model in SD rats with uniform depth, high reproducibility and good stability.