This study investigated whether negative stereotypes are responsible for the effect of ASD knowledge on social distance from individuals with ASD among college students. A sample of 869 neurotypical Chinese college students completed a cross-sectional survey to assess social distance, ASD knowledge, and negative stereotypes. Pearson correlation analysis yielded significant correlations between social distance, ASD knowledge, and negative stereotypes. Multiple mediation analysis showed that negative stereotypes mediated the link between social distance and ASD knowledge. Specifically, greater ASD knowledge predicted reduced social distance through decreased stereotyping related to dangerousness, personal responsibility for the disorder, and discontinuity, but also predicted greater social distance through increased stereotyping related to social inappropriateness. The findings deepen our understanding of the association between ASD knowledge and social distance by revealing the mediating role of negative stereotypes, and provide information that can help improve anti-stigma initiatives in college settings.