The experience gained from peers' innovation failure serves as a key knowledge source for enterprises to refine their knowledge systems, and profoundly influences their future innovation output. Based on the signaling theory and the organizational learning theory, using the data of China's A-share listed companies from 2014 to 2022, this paper employed a dual fixed-effects model and a moderation effect model to systematically explore the employee-level failure learning mechanism through which peer firms' innovation failure information affects corporate innovation output. The findings are as follows: (1) Peer firms' innovation failure information has a significant positive effect on corporate innovation output, and this conclusion remains valid after a series of robustness tests; (2) The mechanism test based on the AMO theory showed that employees' "learning ability (A) - learning motivation (M) - learning opportunity (O)" significantly strengthens the positive effect of peer failure information on enterprise innovation output, with learning motivation having the strongest moderating effect, followed by learning opportunity, and then learning ability the weakest; (3) The heterogeneity analysis showed that peer innovation failure information plays a stronger role in promoting innovation output for growing enterprises, non-state-owned enterprises and enterprises with fierce industry competition. The conclusions have not only highlighted the importance of external heterogeneous knowledge sources for enterprise innovation, but also enriched the mechanism research on improving enterprise innovation output from the perspective of human capital.