This study investigates how the information characteristics and user trust of Korean beauty social platform influencers (K-COS SPIs) affect new product acceptance among Chinese millennial consumers. A total of 415 responses were collected through an online survey, and structural equation modeling (SEM) was used to examine the proposed relationships. The findings demonstrate that the perceived usefulness, interest, reliability, and expertise of information provided by K-COS SPIs significantly influence both user trust and acceptance of new products. Additionally, user trust mediates the relationship between information characteristics and new product acceptance. The study also reveals that brand familiarity and previous purchase experience play moderating roles: brand familiarity enhances the impact of information characteristics on trust and acceptance, while purchase experience moderates trust formation. These results highlight the strategic importance of influencer marketing in the K-beauty industry, especially in rapidly evolving digital markets. The study contributes to the theoretical understanding of influencer effectiveness and provides practical insights for global K-beauty brands seeking to increase consumer acceptance of new products. Suggestions for future research and implications for brand communication and consumer engagement are also discussed.