This paper explores the relationship between Machiavellianist personality and college students’ honesty, and the role of emotional and moral identity between them. A total of 579 college students were tested using the Big Six Personality Scale, the Machiavellianist Person Scale, the Positive and Negative Emotions Scale, and the Honesty Scale. The results showed that: (1) Machiavellianist personality was positively correlated with negative emotions and honesty, and negatively correlated with positive emotions and moral identity. (2) Positive emotions and negative emotions play a significant role in mediating the relationship between Machiavellianist personality and honesty. (3) Moral identity plays a significant moderating role in the relationship between positive emotion, negative emotion and honesty. Conclusion: Machiavellianist personality can not only directly predict honesty positively, but also affect honest behavior through positive emotions, negative emotions, and moral identity.