<p>This paper aims to explore the mechanism of the impact of artificial intelligence usage on employee job performance, with a focus on analyzing the mediating effects of work concentration and self-efficacy, as well as the moderating role of conscientiousness personality. Based on 513 valid samples collected through questionnaires, the data were analyzed empirically using IBM SPSS 27.0 and Mplus8.3. Descriptive statistics, reliability and validity tests, correlation analysis, regression path analysis, and tests for mediating and moderating effects were employed for verification. AI usage significantly enhances employee job performance, and this effect is fully mediated by work concentration and self-efficacy. Conscientiousness moderates the link between AI usage and self-efficacy—but not work concentration—indicating differentiated roles of personality in technology–employee interactions. These findings clarify both the internal mechanisms and boundary conditions through which AI usage influences performance. This research not only enriches the theoretical framework of the relationship between AI usage and employee performance but also provides practical implications for organizations to rationally utilize AI technology, stimulate employee potential, and enhance overall performance.</p>