Homework has always been a concern for many families and researchers. Since the 1920s, research on homework has a history of over a hundred years. Especially since the 21st century, researchers have combined homework with the latest advances in educational psychology and used statistical methods such as multi-layer modeling to process hierarchical nested data in homework, which has provided people with a more direct understanding of the variables in homework, the correlation between variables, and the relationship with student development, and constructed homework models. At the same time, research on homework is not limited to the United States, and researchers from countries and regions such as China and Europe have also conducted active research on this. However, the relationship between homework and student performance improvement has not been fully clarified.