Delayed wound healing is one of the most challenging clinical complications of diabetes mellitus (DM) and is related to the excessive production of reactive oxygen species (ROS). Photobiomodulation (PBM) can promote the healing of delayed wounds in DM patients. We studied the effect of PBM on the active oxygen homeostasis of human embryonic skin fibroblasts (CCC-ESFs) that were cultured in a high glucose environment, and explored the effect of PBM on improving oxidative stress injuries. CCC-ESFs were cultured in vitro, and the cells were randomly divided into control group (normal glucose group and high glucose group) and 808 nm laser irradiation group (power density: 10, 20, and 40 mW/cm²; energy density: 1.5, 3, 6, and 12 J/cm²). After 48 hours of high glucose modeling, the experimental group was irradiated with a laser and we measured the cell proliferation, ROS content, total superoxide dismutase, total antioxidant capacity, mitochondrial membrane potential and the expression level of the related cytokines. The results show that cell proliferation activity was reduced, ROS content was significantly increased, antioxidant capacity was decreased and cell apoptosis was increased in the high glucose environment; however, the proliferation effect of the cells was not significantly improved after 808 nm laser irradiation, but ROS content of the cells decreased, the expression of antioxidant enzymes showed an upward trend, and the expression of pro-inflammatory cytokines decreased. These results show that PBM can repair oxidative stress damage, regulate inflammatory responses, and promote wound healing under a high glucose environment.