From the perspective of behavioral finance, we select the Shanghai and Shenzhen A-share listed companies that completed the M&A activities from 2015 to 2017 as a sample to study the influence of managers overconfidence and payment-method on M&A performance. In addition, under the condition of controlling the overconfidence variables of managers, the payment method is taken as the regulating variable, and the interaction item between the payment method and the overconfidence of managers is added to the model to study the regulating effect of the payment method on the overconfidence of managers and the performance of acquired companies. The results show that: the managers忆overconfidence has a significant negative impact on the performance of the acquired company; the cash payment-method has a significant positive impact on the performance of the acquired company; the cash payment-method has a positive regulation on the relationship between the managers忆overconfidence and the acquired company忆s performance.