As an important form of drug delivery, the transdermal drug delivery system has demonstrated unique advantages and potential in the treatment of various diseases such as chronic pain and skin diseases. However, in the prevention and treatment of skin photo-damage, it still faces issues like low transdermal efficiency and poor drug retention. Therefore, there is an urgent need to develop a highly efficient and safe drug delivery technology. In this study, solid lipid nanoparticles loaded with vitamin A palmitate (VAP-SLN) were designed and prepared to improve the encapsulation efficiency and stability of vitamin A palmitate (VAP), aiming to enhance the therapeutic effect of VAP on skin photodamage via transdermal drug delivery. The high-speed shearing and high-pressure homogenization method were used to prepare VAP-SLN. After prescription screening, it was determined that VAP-SLN was mainly composed of solid lipid glyceryl behenate and liquid lipid medium-chain triglycerides, phospholipids, Tween 80, alkyl polyglycosides and VAP. The prepared VAP-SLN had a particle size of approximately 200 nm, a spherical structure, and an encapsulation efficiency of 91.1%. Its phase transition temperature was 59.8 ℃. This characteristic endowed it with excellent thermal stability and significantly improved the stability of the encapsulated VAP. VAP-SLN exhibited the advantage of sustained-release characteristics and intradermal retention, which could significantly prolong the local drug action and enhance the transdermal drug delivery efficiency. At the cellular level, VAP-SLN exhibited good cellular uptake and retention ability in HaCaT cells, thereby enhancing the effect of VAP in alleviating cellular oxidative stress and inflammatory responses. In the mouse skin photodamage model, VAP-SLN could effectively improve the reduction of collagen fibers and the decrease in collagen volume in photodamaged skin, restore the epidermal thickness and morphology to a healthy level, and effectively prevent and treat ultraviolet-induced skin damage. The animal experiments were approved by the Institutional Animal Care and Use Committee of Yantai Institute of Materia Medica (Approval No.: 20250701-01). In conclusion, VAP-SLN significantly alleviates skin photodamage through antioxidant and anti-inflammatory mechanisms, providing a new strategy for the transdermal delivery of VAP and the prevention of skin photodamage.