After reports of self-driving car accidents, public acceptance of autonomous vehicles (AVs) has shown a downward trend. To explore factors influencing this decline of acceptance and to bring acceptance back to the normal range, this study proposed a new factor, human-manipulated risk perception (HMRP), in the context of human-machine collaborative driving. On this basis, we explored the relationship between HMRP and acceptance of AVs and the mechanism of influence. Furthermore, we proposed a behavioral intervention approach to mediate and moderate the relationship between the two. First, an improved acceptance model was developed based on HMRP. Subsequently, a survey was executed, and 300 valid questionnaires were returned. Test results for the improved model showed that HMRP had a significant negative effect on acceptance of AVs. A hybrid model of mediation and moderation was designed, and user experience was introduced as a moderating variable. The results showed that the proposed behavioral intervention strategy was effective in attenuating the negative effect of HMRP on acceptance of AVs. This study provides theoretical support and methodological guidance for developing behavioral interventions to improve user acceptance.