ITPV system provides rich content and high-definition picture,IPTV STB is crucial.SWF file is the main Internet multimedia resource file format,but the IPTV STB can not play SWF files.IPTV STB for SWF files do not support technical issues,we present a way to play the SWF files by IPTV STB.Mainly through the analysis of the characteristics of SWF,the decoder design is completed by using PNX8550 as core.Storage and playing of SWF files is implemented and the function of STB is expanded effectively.