Psychological disorders have become increasingly prevalent [Liang, 2021]. Among 875 cases, 33.03% of high school students in Mainland China possess some psychological problems [Liang, 2021]. Research has shown that successful musical engagement positively affects physical, social, educational, cognitive, and emotional health [Wang (2022).]. Unfortunately, Chinese teenagers aren't thoroughly studied the connection between musical training and mental health [Pang et al. (2017)]. Also, no statistically significant association between music playing and psychological well-being is seen in previous research [Wesseldijk et al. (2019)]. So, this study investigates how time spent practicing musical instruments influences the intensity of jitteriness among high school teenagers (15~18 years old) to provide insights about mental health-directed musical education in mainland China. A web-based, cross-sectional survey was conducted with a convenience and snowball sample of 200 teenagers from mainland China across 11 provinces. Models were conducted hierarchically using linear regression. In the univariate model, time spent practicing musical instruments weekly was associated negatively with the intensity of jitteriness (β=-0.151, p-value=0.033). In the multivariant model, participants' time spent practicing musical instruments per week was significantly and negatively associated with the intensity of jitteriness (β=-0.312, p-value=0.001), adjusted for confounding variables: total time spent on playing musical instruments, positive emotion intensity, negative emotion intensity (other than jittery), and age. The model was built using simple linear regression with r2=0.267. This study shows a significant negative association between weekly time spent practicing musical instruments and the intensity of negative emotions.