This study explores the effects of embedding Socio-Scientific Issues (SSI) into vocational design education on students' ethics awareness, social responsibility, and design performance. A mixed-methods quasi-experimental design was employed, involving 80 vocational design students divided into an experimental group (SSI-based workshop) and a control group (traditional workshop). Ethics awareness and social responsibility were assessed using the Attitudes toward the Ethics of Artificial Intelligence (AT-EAI) and the Chinese College Student Personal Responsibility Scale (CCSPRS), respectively. Performance was evaluated using a rubric-based assessment. Qualitative data were obtained from students' reflective reports. ANCOVA results revealed that the experimental group significantly outperformed the control group in posttest scores of ethics awareness and social responsibility (p < 0.05). Additionally, they scored significantly higher in ethical sensitivity and user experience, though not in scientific accuracy creativity, or visual expression (p < 0.05). Thematic analysis indicated that students in the SSI group demonstrated deeper ethical reasoning, increased empathy, and a redefined sense of the designer's social role. SSI-based teaching not only enhances students' ethical and civic competencies but also influences how they embed values into design. It highlights the transformative potential of SSI pedagogy in vocational design education.