The family plays an immensely crucial role in the development of adolescents, significantly influencing their behavioral patterns. To explore the impact mechanism of the parental mediation (active mediation, restrictive mediation, and parental monitoring) on adolescents' smartphone addiction, and analyze the chain-mediating role of basic psychological needs and fear of missing out (FoMO). Parental Mediation Scale, Smartphone Addiction Scale, Basic Psychological Needs Scale and Fear of Missing Out Scale were administered to 5,841 adolescents. The sample comprised 2,772 boys (47.46%) and 3,069 girls (52.54%) with an age range of 11.5 to 15.3 years (M = 13.35, SD = 1.29). The results indicated that active mediation could negatively predict adolescents' smartphone addiction, whereas restrictive mediation and parental monitoring could positively predict adolescents' smartphone addiction; and after controlling for sex and age, basic psychological needs had a separate mediating effect on parental mediation and smartphone addiction. Moreover, this study observed a chained mediating effect between basic psychological needs and FoMO on the relationship between parental mediation and smartphone addiction. Meanwhile, FoMO did not have a mediating effect on the relationship between parental mediation and smartphone addiction. Based on social cognitive theory and self-determination theory, this study innovatively integrates parental mediation, adolescents' basic psychological needs, fear of missing out, and smartphone addiction into a coherent model. More importantly, it separately examines the effects of active mediation, restrictive mediation, and parental monitoring within the same group of participants, allowing for a cross-comparison of the three types of parental mediation in the study. This provides a theoretical reference for reducing adolescents' smartphone addiction.