The study explored the impacts of machine translation on Chinese university students’ L2 academic writing, especially on the motivation of using machine translation and the writing strategies with the aid the machine translation (MT). With the technology advances proceeding unimpeded, MT, as one of the artificial intelligence-based technology, was booming in the L2 academic writing. Although many previous studies examined the influence of using MT on the quality of L2 academic writing, few study paid attention to the students’ psychological activities and writing strategy during the writing process. Therefore, viewing the academic writing as a process, this study employed the Technology Acceptance Model to explore how motivation of using MT influenced the final writing strategy selection by analyzing the factors that impacted the motivation. Semi-structural interview was applied in this study to explore the thoughts and experience of eight Chinese university students in using MT in their L2 academic writing. After collecting and analyzing the qualitative data, the study found that with the comprehensive influence of external variables, the psychological features of Chinese university students largely influenced the writing strategies with the assistance of MT in L2 academic writing. This study provided possible insights into how MT shapes the writing strategies, and thus suggested some recommendations for higher education institutions and teachers of English academic writing on how to better use MT in academic writing so that students can be delivered with relevant guidance in this respect.