Abstract: The public spaces in primary school campuses play a crucial role in the cognitive exploration and emotional development of school-aged children. However, the lack of acoustic design may weaken environmental perception and trigger negative emotions. This study aims to explore the mechanism by which the soundscape in primary school public spaces promotes children’s cognitive and emotional functions. Based on human factors engineering methodologies, an experiment is conducted using audiovisual virtual scenes comprising seven types of soundscapes and three types of spatial control variables. Eye-tracking and electrodermal and heart rate data from 101 child participants are analyzed to examine the effects of soundscape variations on children’s environmental perception, cognitive load, and emotional regulation. The result points out that soundscapes with bio-ecological attributes can significantly stimulate children's awareness of the green natural environment in the campus, among which bird songs are more effective in creating a low-arousal cognitive recovery state compared to leaf rustling and insect chirping sounds. Campus life sounds such as children’s laughter and ball hitting significantly enhance non-directional attention and happy emotions, while informational signals related to teaching and popular science may increase cognitive load and psychological pressure. Road traffic noise is shown to significantly suppress visual exploration frequency and vagus nerve activity, thereby increasing the risk of mental fatigue. Furthermore, the cognitive psychological effects of soundscapes vary depending on the type of space and are driven by individual abilities. In semi-open elevated spaces, insect sounds are more effective in stimulating natural awareness than bird songs, and laughter has a more significant benefit on attention and emotional recovery than natural sounds. Finally, based on multimodal physiological evidence, the study proposes a differentiated campus soundscape design strategy aimed at focused learning and stress recovery.