<p>Previous research has demonstrated a bidirectional relationship between loneliness and technological addictions (i.e., internet addiction and smartphone addiction) among adolescents. However, given the distinct psychological mechanisms and risk factors associated with specific mobile applications, it is essential to explore this relationship in the context of short-form video addiction. Moreover, few studies have explored mechanisms explain the bidirectional relationship between loneliness and short-form video addiction. Therefore, the present study aimed to determine whether (i) distress intolerance mediates the bidirectional relationship between loneliness and short-form video addiction and (ii) family socioeconomic status and gender moderate these associations. At Time 1, a total of 1227 Chinese adolescents aged 14 to 19 years (43.4% boys; M_<i>age</i> = 16.00 years; <i>SD</i> = 0.61) participated in a three-wave longitudinal study with six-month intervals. Results from cross-lagged panel models showed a positive bidirectional relation between loneliness and short-form video addiction, and that distress intolerance mediated the bidirectional relationship between loneliness and short-form video addiction. Moreover, the effects of loneliness on short-form video addiction were stronger among adolescents with low family socioeconomic status, while the effects of distress intolerance on short-form video addiction were stronger among adolescents with high family socioeconomic status. The findings highlight the importance of addressing loneliness and fostering distress tolerance to reduce short-form video addiction.</p>