Objective: To analyze the relationship between 24 h movement behaviors and cognitive function in children and adolescents, as well as the isotemporal substitution benefits, in order to provide a basis for developing cognitive development intervention strategies among children and adolescents. Methods: Relevant studies were searched in the Web of Science, PubMed, Embase, EBSCO, and China National Knowledge Infrastructure databases from their inception to November 30, 2024. Systematic evaluation was performed after document screening, data extraction and quality assessment. Results: A total of 24 highquality studies were included, comprising 35 295 children and adolescents aged 3-18 years. Adhering to the 24 h activity guidelines was associated with better cognitive performance (19 studies). Additionally, substituting 5-30 minutes per day of moderate to vigorous physical activity (MVPA) or sleep (SLP) for sedentary behavior (SB) or light physical activity (LPA) were associated with improvements in cognitive function (7 studies). There were inconsistencies in the effects of different types of SB (learning or entertainment) on cognitive function. Conclusions Adherence to the 24 h activity guidelines supports cognitive development in children and adolescents, with MVPA and SLP as key intervention targets. Increasing the proportion of MVPA, ensuring adequate SLP, and limiting recreational SB and screen time might be helpful to enhance the combined benefits of these three behaviors.