To study the healing effect of different therapeutic doses of red light on acute wounds of type Ⅰ diabetes SD rats. 2 weeks after intraperitoneal injection of Streptozocin (60 mg/kg) solution, rats that peripheral blood sugar over 16.7 mmol/L were considered of diabetes models. Sixty diabetic rats were randomly divided into 5 groups: control group (L0, no treatment), treatment group 1 (L1, 12 J/cm2), treatment group 2 (L2, 24 J/cm2), treatment group 3 (L3, 48 J/cm2), and treatment group 4 (L4, 96 J/cm2). Two acute wounds were made symmetrically on both sides of the midline of the rat back with a hole punch of 8 mm diameter. One day later, wound was irradiated with red light of wavelength of 633 nm±10 nm at different energy densities of each group. The wounds were photographed on day 0, 3, 7 and 10 after punching. On day 3, 7 and 10, 4 rats were randomly selected for wound sampling. After paraffin embedding, HE staining, Masson staining, CD31 immunohistochemical staining and CD68 immunofluorescence staining were performed. Results: The wound healing rate showed that red light treatment can accelerate wound healing, and the effect of L3 group was most significant. HE showed that re-epithelialization of wounds in the treatment groups were accelerated and L3 was the best at day 7.CD31 immunohistochemical staining showed that treatment groups could promote angiogenesis and L3 and L4 were the most prominent.CD68 immunofluorescence showed that treatment groups could reduce the degree of wound inflammatory infiltration at the 10th day, and the positive rates of L2 and L3 were the lowest. Conclusion: Within the scope of the energy density of the experiment, red light can promote type Ⅰ diabetes SD rats back wound healing, and the most notable promoting effect energy density is 48 J/cm2.