Objective:To examine the impact of returned migration experience on the prevalence of non-sui-cidal self-injury(NSSI)and its associations with childhood emotional maltreatment(EM),social support and sleep quality.Methods:A total of 3 901 middle school students in Guizhou Province were investigated with the Adoles-cent NSSI behavior Questionnaire,Childhood Trauma Questionnaire-short Form(CTQ-SF),Adolescent Social Sup-port Scale,and Pittsburgh Sleep Quality Index(PSQI).Results:The prevalence of NSSI among middle school students in Guizhou province was 22.8％,with the rate of 27.3％among returned migrant middle school students.Social support and sleep quality partially mediate the relationship between childhood EM and NSSI in mid-dle school students,with effect sizes of 0.06.The EM scores of returned migrant middle school students(β=-0.62)and non-returned migrant middle school students(β=-0.50)were negatively correlated with social sup-port scores in childhood.The sleep quality scores of returned migrant students(β=0.22)and non-returned migrant students(β=0.14)were positively correlated with NSSI scores.Conclusion:The prevalence of NSSI in returned migrant students is higher.Social support and sleep quality play an important role in the relationship between child-hood EM and NSSI in middle school students.The relationship between childhood EM and social support,sleep quality and NSSI in returned migrant middle school students is stronger than that in non-returned migrant middle school students.

Objective:To examine the impact of returned migration experience on the prevalence of non-sui-cidal self-injury(NSSI)and its associations with childhood emotional maltreatment(EM),social support and sleep quality.Methods:A total of 3 901 middle school students in Guizhou Province were investigated with the Adoles-cent NSSI behavior Questionnaire,Childhood Trauma Questionnaire-short Form(CTQ-SF),Adolescent Social Sup-port Scale,and Pittsburgh Sleep Quality Index(PSQI).Results:The prevalence of NSSI among middle school students in Guizhou province was 22.8％,with the rate of 27.3％among returned migrant middle school students.Social support and sleep quality partially mediate the relationship between childhood EM and NSSI in mid-dle school students,with effect sizes of 0.06.The EM scores of returned migrant middle school students(β=-0.62)and non-returned migrant middle school students(β=-0.50)were negatively correlated with social sup-port scores in childhood.The sleep quality scores of returned migrant students(β=0.22)and non-returned migrant students(β=0.14)were positively correlated with NSSI scores.Conclusion:The prevalence of NSSI in returned migrant students is higher.Social support and sleep quality play an important role in the relationship between child-hood EM and NSSI in middle school students.The relationship between childhood EM and social support,sleep quality and NSSI in returned migrant middle school students is stronger than that in non-returned migrant middle school students.