Abstract The debate over whether the general population shows positive or negative attentional bias persists. Some studies indicate that attentional bias varies individually rather than being a common trait. This study explored the relationship between individuals’ trait anxiety and their attentional bias and its neural mechanisms. Seventy adults with varying trait anxiety levels participated in an emotional competition search task. In the competition condition, a happy and a angry face were presented among neutral faces, with one as the target and the other as the distractor; while in the non-competition condition, one happy or angry face was presented among the neutral faces. The N2pc component of event-related potential (ERP), an attentional selection index, was used to measure attentional bias. Results showed a significant correlation: lower trait anxiety was associated with a stronger positive bias, while higher levels were linked to a more negative bias. Importantly, this anxiety-associated attentional bias specifically manifested in bottom-up processes and the emotion-competition condition. Our research offers electrophysiological evidence indicating that individuals’ trait anxiety is associated with the direction of attentional bias, and, for the first time, discloses its neural mechanism—emerging in stimulation-driven attentional processes, which has implications for cognitive interventions for anxiety disorders.