Nowadays, due to lifestyle changes, the number of young people suffering from chronic non-specific low back pain (CNLBP) is gradually increasing. The recent guidelines for the treatment of low back pain emphasize that exercise therapy is the preferred treatment method for CNLBP. This study take ordinary college male students with CNLBP as objective of the study, focused into how core stability training affected the pain and muscle function of the CNLBP of youth. Herein, 60 male subjects were randomly divided into a control group and an experimental group, and conducted a randomized control trial in the Sports Rehabilitation Laboratory of Guangxi Normal University from September to October 2023. The control group received traditional waist strength training, while the experimental group received core stability training. VAS scores, pain symptoms scores and clinical efficacy grades were evaluated. Waist muscles fitness was evaluated, including back muscle strength, the prone upper body up's static holding time, 1-min modified sit-ups' pcs, the supine abdominal curling's static holding time and the supine leg raising's static holding time. Waist movement function was also evaluated using oswestry disability index (ODI) questionnaire. Surface electromyographic (EMG) signals were collected from rectus abdominis, erector spinae and multifidus. The independent sample t-test was used to compare groups, and the paired sample t-test was used for the data comparison before and post-exercise within the group. The results of the study found that CNLBP was improved in both the experimental and control groups in the post-exercise. Compared to pre-exercise, there are significant decrease in the VAS scores (95%CI: 2.51 to 6.51, p = 0.000), pain symptoms scores (95%CI: 2.95 to 3.55, p = 0.000), waist movement function's evaluation scores for ODI (95%CI: 2.23 to 4.31, p = 0.000), rectus abdominis' IEMG values (95%CI: 2.29 to 4.39, p = 0.000), erector spinae and multifidus' IEMG values (95%CI: 2.18 to 4.45, p = 0.000) of experimental group in the post-exercise. Compared to pre-exercise, there are significant improvement in the back muscle strength (95%CI: 12.85 to 19.49, p = 0.000), the prone upper body up's static holding time (95%CI: 9.67 to 19.17, p = 0.000), the 1-min modified sit-ups' pcs (95%CI: 8.56 to 18.12, p = 0.000), the supine abdominal curling's static holding time (95%CI: 6.73 to 19.14, p = 0.000), and the supine leg raising's static holding time (95%CI: 8.21 to 18.35, p = 0.000) of experimental group in the post-exercise. In the post-exercise,there are significant lower in the VAS scores (95%CI: 1.41 to 4.98, p = 0.000), pain symptoms scores (95%CI: 1.14 to 1.79, p = 0.011), waist movement function's evaluation scores for ODI (95%CI: 1.13 to 2.25, p = 0.000), rectus abdominis' IEMG values (95%CI: 2.36 to 4.47, p = 0.000), erector spinae and multifidus' IEMG values (95%CI: 2.24 to 4.23, p = 0.017) of experimental group than those of control group. In the post-exercise, there are significant higher in the recovery rate (p = 0.000), the prone upper body up's static holding time (95%CI: 4.16 to 8.32, p = 0.008), and the supine abdominal curling's static holding time (95%CI: 3.89 to 7.44, p = 0.000) of experimental group than those of control group. Therefore, it can be concluded that core stability training is significantly effective in treating CNLBP in youth, enhancing lower back muscle function. This therapeutic effect is primarily attributed to the improvement in muscle function.