Photodynamic therapy (PDT) is an emerging therapeutic strategy for hypertrophic scars (HS), which is heavily dependent on reactive oxygen species (ROS) generation. However, the unsatisfactory delivery and excitation of 5-aminolevulinic acid (ALA, a commercial photosensitizer in dermatology) result in an insufficient ROS generation, and thus limit the clinical application of PDT treating HS (HS-PDT). Consequently, sophisticated transdermal co-delivery nanoethosomes (named A/A-ES) with ALA and Au nanotriangles (AuNTs) in cores are prepared via an in-situ seed-mediated growth method, and then applied to improve HS-PDT through localized surface plasmon resonance (LSPR)-enhanced ROS generation. A/A-ES display a satisfactory performance in co-delivery in HS tissue with sufficient protoporphyrin IX production and LSPR effect in cytoplasm, which is beneficial for ALA excitation as well as ROS generation. In vitro/vivo studies reveal that A/A-ES significantly improve HS-PDT in promoting to fibroblast apoptosis and collagen remodeling through LSPR-enhanced ROS generation. Therefore, this study provides a feasible strategy that integrates transdermal delivery and LSPR to enable the beneficial effects of HS-PDT through boosting the delivery and excitation of ALA.