Current social issues such as bullying, online violence, and local conflicts are all hot topics in the field of psychology, and these phenomena are related to dehumanization, but research on dehumanization from a non-western background has been rare. As a key factor influencing individual behavior, attachment has not been incorporated into the relevant research on dehumanization. Therefore, this study presented empirical evidence to explore the relationship between adult attachment (both trait and state) and dehumanization, the samples were college students from China. Study 1 (N = 705) used latent profile analysis to verify the four types of adult attachment(i.e., preoccupied , secure, fearful, and dismissiving)and found differences in the impact of different attachment types on dehumanization. Study 2(N = 281) activated secure attachment, and found differences in the impact of three types of state attachment (i.e., security, avoidance, and anxiety)on dehumanization, as well as the positive predictive effects of security and avoidance on dehumanization. This research originally proved the relationship between adult attachment and dehumanization, providing new perspectives for exploring the psychological mechanisms behind dehumanization, and offering new paths for the prevention and intervention of dehumanization.