Recently,　the　usage　of　short-video　applications　(apps)　has　become　widespread　and　the　potential　influence　of　short-video　apps　use　on　individuals　has　attracted　the　attention　of　researchers.　However,　few　studies　have　explored　the　influence　of　short-video　apps　use　on　adolescents＇　self-concept　clarity.　This　study　aimed　to　examine　the　relationship　between　short-video　apps　use　and　self-concept　clarity　among　adolescents　and　whether　this　relationship　is　mediated　by　flow　and　social　media　self-expansion.　A　total　of　721　Chinese　adolescents　completed　questionnaires　on　intensity　of　short-video　apps　use,　flow,　social　media　self-expansion,　self-concept　clarity,　and　SNS　use　intensity.　The　results　revealed　that　short-video　apps　use　was　negatively　related　to　self-concept　clarity　among　adolescents.　Flow　mediated　the　association　between　short-video　apps　use　and　self-concept　clarity.　Moreover,　the　relationship　between　short-video　apps　use　and　self-concept　clarity　was　sequentially　mediated　by　flow　and　social　media　self-expansion.　These　findings　offer　new　insights　into　our　understanding　of　adolescents＇　self-development　in　the　context　of　digital　media　and　provide　implications　for　fostering　healthier　online　experiences　among　adolescents.