Currently, there are a vast number of Chinese students taking IELTS each year, but there are scarce studies regarding to how this high-stakes test affects Chinese students. From the perspective of test impact and second language acquisition theories, this study investigates Chinese students' perceptions of IELTS's affective impact in their preparation and test-taking experiences, with particular focus on how IELTS affects students' learning goal, motivation, and anxiety. Due to the complexity of test impact and second language acquisition, this study adopted a mixed-method research, including questionnaire survey and interviews. Seventy-six students who had taken IELTS more than once were invited to complete online survey, and ten out of those surveyed were invited to attend semi-structured interviews. Both quantitative data and qualitative data were analysed. As shown in the findings, the most important affective impact of IELTS was its influence on students' short-term learning goal. Also, IELTS had an influence on students' motivation but did not affect students' anxiety to a large extent. Moreover, IELTS's influence on students' learning goals was greater than its influence on motivation. Besides, because students clarified their learning goals, specifically short-term learning goals, they were motivated and their anxiety was reduced. However, in accordance with the findings, IELTS might potentially have negative impact on students' long-term learning goals, but the data from the research in the study are not possible to enable me to say anything specific about how much it could negatively impact long-term learning goals. In the future, it is suggested that the impact on students' long-term learning goals be researched on.