Flexibility is the most distinguishing characteristic for organic solar cells (OSCs) that outweighs the inorganic photo-voltaic technologies. However, the current power conversion efficiencies (PCEs) of flexible OSCs still lag behind those of rigid counterparts. This is mainly due to the lack of high-performance flexible transparent electrodes (FTEs) that simultaneously offer low resistance, high transparency, and low surface roughness. Traditional indium tin oxide (ITO) conductive films are widely used in organic optoelectronic devices due to their excellent optoelectric properties. However, the intrinsic brittleness of ITO and the scarcity of indium have limited its development and application in flexible devices. Therefore, it is very important and urgently needed to develop new high-performance flexible transparent conductive materials and apply them to flexible OSCs. Among the various FTE materials, metal nanowires, especially silver nanowires (AgNWs), have become the star conductive material in FTEs with their excellent optoelectric properties and flexibility. Meanwhile, the flexible OSCs using AgNWs-based FTEs have also been extensively studied, and great progress has been made in the past decades. In this review, the recent progress of flexible OSCs with AgNWs-based FTEs has been summarized, focusing on the impact of the AgNWs-based FTEs properties on the performance of flexible OSCs. Finally, the prospects and challenges of flexible OSCs are discussed.