<p>The upsurge of translation technology has fostered complex socio-cognitive communication environments where metacognition emerges as a crucial mediator among translators and other relevant agents. Most research has centered on individual translators, and evidence is scarce on how translation teams navigate such environments and how individual metacognitive activities impact the teams’ translation performance. This study bridges this gap by exploring trainees’ metacognitive activities in the technology-assisted project. This study split between higher- and lower-achieving teams based on their project outcomes and explored their socio-cognitive behaviors and team-averaged metacognitive differences. Data were collected and cross-referenced from self-reflection reports, focus group interviews, questionnaires, log data, chat data, and classroom observations. The analyses suggest that (1) all the teams engaged in various collaborative inquiries; higher-achieving teams prioritized mutuality, engaged in more self-directed activities, and displayed greater learner autonomy, whereas lower-achieving teams relied more on instructor scaffoldings and participated less actively in discussions and complex tasks; (2) teams in both conditions had similar levels of metacognitive knowledge of person and strategy, but the higher-achieving teams showed higher metacognitive knowledge of task and metacognitive regulation; (3) higher-achieving teams exhibited more critical self-evaluations and more analytical approaches to tasks, indicating their enhanced metacognitive awareness than lower-achieving teams. In light of these results, metacognition and self-autonomy are important in translation and other complex communication tasks.</p>