The purpose of this study was to explore the role of the attentional alerting network in spatial perceptual processing in youth athletes under different emotional states. Two hundred and fifty participants were recruited to assess alerting efficiency using the Attention Network Test and were divided into high and low alerting efficiency groups based on the front and back 27% of the alerting scores as a dividing metric. Subsequently, participants completed the Spatial Perception Response Task under different emotionally induced conditions. Results showed a correlation between alerting efficiency and spatial perception, the higher the alerting efficiency, the faster and more accurate the spatial perception response. Emotion and spatial location interacted significantly (p < 0.05), and subjects in the angry emotional state had faster spatial responses to the lower left visual field than those in the happy emotional state. Moreover, an interaction was found for location accuracy (p < 0.05). The high alerting efficiency group showed lower accuracy in the anger state than in the happy state. These findings suggest that alerting efficiency can be used as an objective indicator for assessing the spatial perceptual ability of youth athletes, which provides empirical evidence for mental selection and perceptual training of youth athletes.