There is no consensus on whether adult with autistic traits joint attention (JA) deficits. Additionally, previous studies have mostly been conducted in traditional laboratory settings, lacking ecological validity. This study aimed to address these limitations by using real-life scenarios and functional near-infrared spectroscopy (fNIRS) techniques to investigate the impact of sound cues on JA among individuals with Autistic Traits in China. 23 high autistic trait and 26 low autistic trait adult participated, which examined brain activation during JA in real-life scenarios. The results revealed that high autistic trait adult showed stronger brain activation in the dorsolateral prefrontal regions during JA compared to non-joint attention, and stronger than that of low autistic trait.