Based on the ecosystem theory and the process-person-context-time model, this study explored the combined effects of parental involvement and perceived school climate on academic burnout among 17,289 high school students by using a questionnaire approach. Polynomial regression with response surface analysis found that (1) the combined effect of parental involvement and perceived school climate significantly predicted academic burnout levels among high school students; (2) high school students with high parental involvement and high perceived school climate had lower levels of academic burnout than those with low parental involvement and low perceived school climate; high school students with low parental involvement and high perceived school climate had lower levels of academic burnout than those with high parental involvement and low perceived school climate; (3) gratitude partially mediated the block variables' effects on high school students' academic burnout. This study provides a new explanatory perspective on the underlying mechanisms of academic burnout among high school students and has certain reference value for future intervention research targeting academic burnout.