The daily behaviors of college students are closely related to their subjective well-being. This study conducted a survey on 1165 college students using a questionnaire method, analyzed the current status of subjective well-being, sleep quality, physical activity, and screen time of contemporary college students, and explored the impact of sleep, physical activity, and screen use on subjective well-being. The results show that the subjective well-being of college students is at a medium to high level, and those who are younger, have hobbies, and participate in extracurricular activities have better subjective well-being. Subjective well-being is significantly negatively correlated with sleep quality and screen time, and significantly positively correlated with physical activity. Regression analysis found that after controlling for demographic confounding factors, sleep disorders, daytime dysfunction, self-rated sleep quality, and sleep time negatively predict the subjective well-being of college students, while exercise frequency positively predicts the subjective well-being of college students. The conclusion provides a reference for behavioral guidance to improve the subjective well-being of college students.