In recent years,in fashion industry,especially in clothing market industry,the development of fast fashion brands is very rapid,the accounts in clothing market is more and more,which has become an indispensable part in clothing market field.It can be said the fast fashion brand takes a deep shock for whole clothing market,and it has made some clothing brands take introspection about their traditional and old marketing mode.Fast fashion brands just catch the consumer psychology of current consumers(especially young consumers),a smart of consumers are attracted to buy for its "fair price"," high quality","fashion" and other characteristics.In this paper,the success case of the most successful "H&M" brand is taken as entry point,then the marketing strategy of fast fashion brands is explored and analyzed to find out the "magic weapon" of fast fashion brands’ development,and it is provided some reference and suggestions for marketing strategy improvement of traditional clothing brands.