The introduction of online homework has revolutionized traditional assignment formats, providing students with access to abundant learning resources, a convenient platform for completing assignments, real-time interactive learning opportunities, and accurate feedback. However, there is a paucity of research exploring the perspectives of elementary school students on the use of online homework platforms. This study, rooted in the online learning experiences of elementary school users, introduces three variables--perceived playfulness, perceived interactivity, and flow experience--to extend the UTAUT model. The investigation explores the behavioral intention of elementary school students to use online homework platforms. Data were collected through a questionnaire survey involving 312 elementary school students, and structural equation modeling was employed to analyze 289 valid responses. The results indicate that flow experience, social influence, performance expectancy, and effort expectancy significantly influence the behavioral intention of elementary school students to use online homework platforms. Additionally, perceived playfulness and perceived interactivity indirectly impact students' behavioral intention through the mediation of flow experience. Furthermore, it was observed that students' effort expectancy affects their performance expectancy. In conclusion, this research contributes to a deeper understanding of Chinese elementary school students' behavioral intention to use online homework platforms by reflecting their status and requirements within the context of online homework. The findings provide valuable insight for optimizing and upgrading online homework platforms as well as their pedagogical application.