The existence of prejudice in human beings is innate and ubiquitous, making it a classic topic of cross-cultural research. However, the conventional research paradigms in fields like psychology and sociology have tended to take a narrow approach, lacking a unifying theoretical perspective and comprehensive indicator models. Integrated threat theory builds upon the systematic exploration of prejudice by social identity theory, realistic group conflict theory and symbolic racism, elevates the focus on threat to the central position of prejudice research, and sets up a process path from multiple antecedents to the consequences of prejudice. Starting from this, the research delves into the academic context of integrated threat theory and elucidates its theoretical framework, trying to apply this theory to intercultural communication in the dimensions of cultural differences, intergroup relations, diversified civilization and marginal groups, so as to deconstruct and reconstruct the core issues. Thus, it provides an expandable direction for exploring the origins of cultural prejudice in navigating local cultural scenes and comprehending the reality logic of multicultural politics and cross-cultural interactions.