At present, there is a lack of relevant literature on functional training for young athletes aged 10-12 years old in China. This project plans to combine functional training with sports training classes. Through 40 young athletes aged 10-12 years old, the impact of functional training on 10-12-year-old athletes is systematically studied. Effects on agility in age-old athletes and exploring its causes. This article uses expert interview methods, experimental methods, mathematical statistics and other methods to analyze the survey results. Before the experiment begins, general information about the research subjects is collected, and then they are divided into experimental groups and control groups, and then a difference analysis is performed to determine the differences between the two groups. After 12 weeks of experimental intervention, the sensitivity quality evaluation indicators of the two groups of students were compared. Results: There was a very significant difference in the experimental group's scores on the hexagonal reaction ball test before and after the experiment (P<0.01), with an improvement rate of 10.8%; the difference between the control group's scores on the hexagonal reaction ball test before and after the experiment was statistically significant (P<0.01). Significance (P<0.05), the average improvement was 4.0%. There was a very significant difference (P<0.01) in the performance of the experimental group in the 4×10m return run before and after the experiment, with an improvement rate of 11.7%; in the control group, there was a significant difference in the 4×10m return run before and after the experiment. The difference was statistically significant (P<0.05), and the average progress rate was 8.0%. Conclusion: Whether functional training or traditional physical training can improve the physical fitness of children aged 10 to 12 years old to varying degrees. Among athletes aged 10 to 12 years old, functional training has a significant promotion effect on improving the speed and flexibility of the 6-angle reaction ball and 4×10 m. Traditional physical training has a significant effect on improving the speed and flexibility of the 4×10 m return run between the ages of 10 and 12 years. Performance is improved to varying degrees, and functional training is more effective. Functional training can increase the interest in sports practice of teenagers aged 10 to 12 years old, and relieve the monotony of training classes to a certain extent.