Objective: To explore the combined effect of health literacy and nonsuicidal selfinjury on suiciderelated behaviors in junior middle school students, so as to provide reference for suicide prevention. Methods: During May to June 2023, a selffilling questionnaire survey was conducted among 7 367 junior middle school students selected by the methods of multistage stratified cluster sampling combined with conventient sampling in Chongqing. And a binary Logistic regression model was established to analyze the association of health literacy and NSSI with suiciderelated behaviors. Results: The detection rates of suicidal ideation, suicide planning, and suicide attempt among junior middle school students were 27.99%, 9.84%, and 4.64%, and the detection rate of NSSI was 38.03%, the rates of possessing total health literacy, functional health literacy, interactive health literacy, and critical health literacy were 62.68%, 66.51%, 54.24%, and 72.65%, respectively. Binary Logistic regression analyses showed that the absence of total health literacy and the three dimensions of health literacy and NSSI were positively correlated with suicidal ideation, suicide planning, and suicide attempt in junior middle school students (OR=1.42-10.30), and there were combined effects (OR=7.43-18.71) (P<0.05). Conclusions Lack of health literacy or the presence of NSSI and their coexistence increase the risk of suiciderelated behaviors, and health literacy level should be improved in junior middle school students to reduce NSSI and thereby prevent suiciderelated behaviors.