The belief in online news has become a hot topic. Previous studies have shown the role of emotion in susceptibility to believing fake news. However, Few studies have explored the effect of empathy on belief in online news. This study investigated the relationships between trait empathy, state empathy, the belief in online news, and the potential moderating effect of the news type. One hundred and forty undergraduates evaluated 50 online news pieces (25 real, 25 fake) regarding their believability, state empathy, valence, arousal, and familiarity. Trait empathy data were collected using the Chinese version of the Interpersonal Reactivity Index. State empathy was positively correlated with affective empathy in trait empathy and believability, and affective empathy was positively correlated with believability. The influence of affective empathy on news belief was partially mediated by state empathy, regulated by the news type (fake, real). We discussed the influence of empathy on the belief in online news and its internal processes. This study explains some unique insights for researchers, practitioners, social media users, and social media platform providers.