Transdermal epidermal growth factor (T-EGF) shows excellent repairing effects on damaged skin and can be widely used in skin care products. Ultraviolet (UV) rays during sunlight exposure cause various types of skin damage. We designed an after-sun repair gel containing 10 mg/kg T-EGF and systematically investigated the clinical soothing and repairing efficacy of T-EGF on acutely photodamaged skin. 30 qualified participants were enrolled to a clinical study where a UV-induced skin redness model on the non-exposed areas of their backs was established. Based on this, we collected Tissue Viability (TiVi) images before and after applying T-EGF gel and analyzed these images to obtain the average TiVi-index values. We also measured the skin erythema index (EI) and skin colour a* value before and after the use of T-EGF gel. The results show that the T-EGF gel significantly reduced skin redness caused by acute photodamage. As the research into T-EGF’s repair capabilities continues to deepen, it holds greater application value and promising development prospects in skincare products.