Adolescent physical and mental development is a perspective that the humanistic sociology of sports focuses on in the field of youth sports. This paper investigates how the use of AI technology in sports will affect the physical and mental development of youth. In order to overcome the shortcomings of small samples, high dimensionality, and high noise in youth physical and mental development data, this paper adopts dimensionality reduction methods such as principal component analysis and linear discriminant analysis to reduce the dimensionality of high-dimensional data. Using the processed data, the physical and mental development data of youth were successfully classified into four categories: social interaction, training intensity, psychological state, and cultural influence. The study on the correlation between the AI model and youth physical and mental development takes soccer as an example and adopts the method of pre and post-tests of actual experiments to select students from a high school to conduct the test of physical and psychological indexes before and after the experiments. Physical and psychological index tests before and after the experiment were significantly better for students in the experimental group using AI technology compared to those in the control group not using AI technology.