Psychological adaptability measures the ability of an individual to adjust himself and regain his balance when dealing with the changes of environment or body and mind. Junior high school students are in the adolescence of rapid physical and mental development, and they often face all aspects of adaptability problems in life. It is necessary to explore their psychological adaptability. Previous studies have shown that emotional intelligence can affect individual psychological adaptability, but most of them are cross-sectional studies, and lack of specific mediating mechanism. Therefore, the purpose of this study is to investigate the predictive effect of emotional intelligence on psychological adaptability and the chain mediating effect of interpersonal quality and adversity belief. In this study, 466 junior high school students were followed up for half a year at three time points. The subjects were asked to fill in emotional intelligence scale, interpersonal quality scale, adversity belief scale and psychological adaptability scale respectively by self-report method. The chain mediation hypothesis model was tested by spss25.0 and mplus7.4. The results implicated that: (1) emotional intelligence, interpersonal quality, adversity belief and psychological adaptability are positively correlated with simultaneity and continuity. (2) T1 emotional intelligence have a positive effect on T3 psychological adaptability (β= .13, p< .05). (3) T2 interpersonal quality mediate the relationship between T1 emotional intelligence and T3 psychological adaptability (.16 < Boot CI <.29). Specifically, the effect of T1 emotional intelligence on T2 interpersonal quality is .66 (p< .001), and the effect of T2 interpersonal quality on T3 psychological adaptability is .34 (p< .001). (4) T3 adversity belief mediate the relationship between T1 emotional intelligence and T3 psychological adaptability (.06 < Boot CI < .13). Specifically, the effect of T1 emotional intelligence on T3 adversity beliefs is .25 (p< .001), and the effect of T3 adversity beliefs on T3 psychological adaptability is .36 (p< .001). (5) T2 interpersonal quality and T3 adversity belief chained mediate the relationship between T1 emotional intelligence and T3 psychological adaptability (.02 < Boot CI < .07). Specifically, the effect of T2 interpersonal quality on T3 adversity beliefs is .18 (p< .01). It is found that emotional intelligence can not only directly affect psychological adaptability, but also indirectly affect psychological adaptability through the mediating effects of interpersonal quality and adversity beliefs and the chain mediating effects of them. This study combined with tracking research method, through six months of three waves of longitudinal data collection to verify the impact of emotional intelligence, interpersonal quality and adversity beliefs on junior high school students' psychological adaptability, which is conducive to further reveal the dynamic mechanism of emotional intelligence on psychological adaptability and the relationship between the variables, and provide some reference and guidance for the education and intervention of psychological adaptability, It has important theoretical and practical significance to promote junior high school students' psychological adaptability.