A layer of polyimide is adopted to improve the adhesive ability between common flexible PET (poly(ethylene terephthalate)), generally used in the FOLEDs (flexible organic light-emitting diodes), and ITO anode. It has been demonstrated by the scrape method that great improvement of the critical load value of flexible conductive substrate and lots of melioration of the substrate's flexibility has been made. Moreover, using such a complex substrate the current density and luminescence of the OLED device are approximately four times as much as those by using common PET substrate.