Background <p>Sub-threshold mental symptoms among adolescents are consistently on the rise, which hurts their academic and health development. Both screen time and adverse childhood experiences (ACEs) are linked to these sub-threshold mental symptoms. However, there haven’t been many studies on adolescents in rural areas of China. This study could offer a useful reference and help for preventing and dealing with sub-threshold mental symptoms in rural Chinese adolescents.</p> Methods <p>This study used a stratified whole population sampling method to look at screen time and ACEs in relation to subthreshold mental symptoms among 6,820 adolescents aged 16 to 18 in the rural areas of China. We performed generalized linear model analyses using both binary and ordinal logistic regressions to explore the associations of screen time and ACEs with subthreshold mental symptoms in these adolescents.</p> Results <p>The rate of sub-threshold mental symptoms detected among adolescents in rural China was 21.9%. When it comes to screen time, 31.9% of the adolescents had less than 60&#xa0;min per day, 51.3% had between 60 and 120&#xa0;min per day, and 16.8% had more than 120&#xa0;min per day. As for ACEs, 39.1% had no exposure, 14.2% had low exposure, and 46.7% had high exposure. The ordered logistic regression analysis revealed that, relative to adolescents who spent less than 60&#xa0;min per day on screens and had no ACEs, those who spent more than 120&#xa0;min per day on screens and had high ACEs exposure were at significantly greater risk for sub-threshold mental symptoms (OR = 2.97, 95% CI: 2.31–3.81, <i>P</i> &lt; 0.001).</p> Conclusions <p>Screen time and ACEs are linked to higher levels of subthreshold mental symptoms among adolescents in rural China. Moving forward, we should work on cutting down screen time and reducing ACEs exposure for these adolescents. This approach may reduce the incidence of subthreshold mental symptoms and enhance the general physical and mental well-being of rural Chinese adolescents.</p>