When people are working on creative tasks, they make progress in conscious thought (CT) and unconscious thought (UT) processes. UT occurs outside conscious awareness, and unlike CT, it is independent of working memory resources. Previous studies suggest UT is more influential under certain conditions, known as the UT effect. Typically, these studies utilize a UT paradigm where participants are divided into CT and UT groups: the CT group reflects on the task, while the UT group engages in a distraction. However, UT effect is inconsistent across studies. This study aims to explore the condition under which UT effect works and how to facilitate it. By manipulating performance-contingent reward, this study compared the creativity of UT and CT in reward and non-reward conditions under a modified UT paradigm (N = 179). Creativity was measured by a divergent thinking task (the unusual uses task). Results indicated the fluency and originality in the reward condition were higher than non-reward condition for the UT group. What's more, UT surpassed CT in fluency and originality only in the reward condition. This study extends UT theory and provides insights in maximizing the benefits of UT, enabling individuals to boost creativity without thinking consciously or consuming working memory resources.