The work aims to analyze the development status, trends and prospects of flexible electronics and flexible substrates to provide references for further development of smart packaging. Starting with flexible substrate materials, the properties of common substrate materials were sorted out; the research status and main integration technologies of flexible electronic device integration were summarized, and its application in packaging was discussed. Paper substrates with good flexibility and degradability can be used as a substrate material for flexible electronic integration. Combining the advantages of flexible printed electronic technology and traditional silicon-based electronic technology, flexible electronic devices are integrated and packaged on flexible substrates through a serpentine interconnection structure to prepare integrated stretchable micro-systems. With the continuous emergence of new printed electronic materials, printing processes, new technologies and new equipment, the integration of flexible electronic devices on flexible substrates and their application in packaging will become a major research hotspot.