The research has created a three-dimensional indicator system to measure the development level of the G20 digital economy，including digital readiness，digital market environment，and digital application capabilities. According to the results of cluster analysis of all indicator data，the G20 digital economy can be divided into six different types of development stages. Based on the evaluation results，the research analyzed the opportunities of the G20 digital economy in the post-pandemic era in driving economic growth，driving digital transformation of enterprises，and improving users’ digital literacy and digital consumption habits. Subsequently，the article analyzed five challenges that the G20 will face：digital infrastructure construction，digital economy theoretical research，digital economic cooperation system，cyberspace governance，and digital product demand. Finally，the study puts forward the G20’s response strategies to strengthen cooperation in five aspects of investment，scientific research，system，governance and consumption in view of opportunities and challenges.