This study aims to explore the comprehensive influence of competition costume on athletes'psychological states and their underlying mechanisms. To achieve this goal, this study employed a mixed-method approach, conducting a questionnaire survey (including a self-developed perception questionnaire of competition uniforms, CSAI-2, and POMS scale) on 88 Chinese high-level sports dance athletes and conducting in-depth semi-structured interviews with 12 of them. Results showed that the "aesthetic experience" and "confidence boost" of the athletes towards the competition costume were significantly positively correlated with their "confidence" and "energy" levels (r = 0.315-0.607 p < 0.01); while "functional comfort" was significantly negatively correlated with "cognitive-somatic anxiety" (r = −0.219, p < 0.05). Qualitative analysis further revealed the underlying mechanisms, extracting three core themes: "psychological empowerment of the battle robe," "functional guarantee of the integration of person and clothing," and "artistic extension of design narrative." In conclusion, this study confirms that sports dance competition costumes are not merely decorative items but are active factors that profoundly influence athletes'psychological states through three key paths: psychological empowerment, functional guarantee, and design narrative. Research results have important theoretical and practical implications for athletes, coaches, and competition uniform designers in optimizing training strategies and design practices.

textile technology, textile products, functional clothing, sports costume design