Abstract As a new social phenomenon, fragmented sleep breaks through the limitations of time and space, and provides self comfort for teenagers to learn entertainment at night, but the moderation of fragmented sleep must be studied. The paper ellucidates the essence of fragmented sleep, probes into the reasons, and optimizes sleep fragmentation in their school lives in the persepctive of adolescents behaviors and mental health, so as to find out the targeted measures of policy support, family-school cooperation and exercise support.