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The repair of wounds is essential for overcoming injuries, but the process often leads to scars, and the formation mechanism is unclear. Interestingly, Bletilla striata polysaccharide (BSP) is a procoagulant and has anti-inflammatory properties to promote wound healing, which has great research value for scarless wound healing. Herein, we developed a transdermal drug delivery system of BSP/chitosan (CS) composite bilayer dissolvable microneedles (CS-AS-BSP MNs) containing asiaticoside (AS) based on a centrifugation method with a polydimethylsiloxane mould that fulfilled the requirements of wound healing and achieved a scar-free effect. The drug release results showed that this system improved the solubility of AS and maintained the stable release of the drug for a long time. Further experiments indicated that CS-AS-BSP MNs had a good antibacterial effect and reduced the proliferation of human scar fibroblasts. The wound healing effect of CS-AS-BSP MNs was evaluated in an experimental full-thickness-wound rat model, which demonstrated that the covered wound healed completely without scars within 3 weeks. Furthermore, CS-AS-BSP MNs downregulated TGF-β1 and COL Ⅰ, which are fibrosis-related genes, to inhibit scarring. In brief, this study provides a new strategy for meeting the clinical requirements of effective scarless wound dressings.