As the population of new residents in Taiwan continues to increase due to the increasingly severe trend of having fewer children, the life and school adaptation of the second generation of new residents in vocational high school (VHS) has received significant attention. This study explores the correlation between interpersonal interaction and school adaptation of Taiwan's new second-generation VHS students. Based on the "Cultural Identity" theory, this study proposed a hypothetical model with "self-identity" as the mediating variable and "perceived organizational support" as the moderating variable. This study collected 60 questionnaires from second-generation VHS students in Nantou County, Taiwan, using a purposive sampling technique in June 2023. The author adopted the Hayes' (2022) SPSS 20 PROCESS procedure to verify the mediation and moderation effects. The result of this study contributes to the literature on multiculturalism and applied psychology. Based on first-hand data collection and statistical analysis, the vital conclusions are as follows: 1. the "interpersonal interaction" of the new second-generation VHS students can effectively predict their "school adaptation"; 2. the "self-identity" of the new second-generation VHS students has presented an excellent mediating role between "interpersonal interaction" and "school adaptation"; 3. "Perceived organizational support" plays an excellent moderating role in the relationship between "interpersonal interaction" and "self-identity" 4. Incorporating "interpersonal interaction," "self-identity," and "perceived organizational support," the hypothetical model could effectively predict the "school adaptation" behavior of the new second-generation VHS students.