Background/Objectives: While deficits in executive attention and alerting systems in children with attention deficit hyperactivity disorder (ADHD) are well-documented, findings regarding orienting attention in ADHD have been inconsistent. The current study investigated the mechanism of attentional orienting in children with ADHD by examining their attentional bias towards threatening stimuli. Furthermore, we explored the modulating role of anxiety levels in ADHD on this attentional bias. Methods: In Experiment 1, 20 children with ADHD and 26 typically developing children (TDC) performed a continuous performance task that included task-irrelevant distractions consisting of angry faces and neutral places. In Experiment 2, 21 children with ADHD and 25 TDC performed the same task, but with angry and neutral faces as distractors. To measure children's anxiety levels, the State-Trait Anxiety Inventory was administered before each experiment. Results: In Experiment 1, results revealed no attentional bias effects in children with ADHD, whereas TDC exhibited attentional capture effects by both types of distractors. However, in Experiment 2, ADHD children demonstrated an attentional bias towards angry faces, which revealed a significant positive correlation with their trait anxiety levels (r = 0.61, p < 0.05). Further analyses combining all ADHD children showed that trait anxiety levels in Experiment 2 were significantly higher than those in Experiment 1. Finally, a significant positive correlation was found between anxiety levels and attentional bias towards angry faces in all ADHD children (r = 0.36, p < 0.01). Conclusions: Children with ADHD exhibited atypical attentional-orienting effects to threats, and their levels of trait anxiety appeared to modulate such attentional-orienting mechanisms.