Electrospinning (E-spinning) and electrospraying (E-spraying) synergism (EES) has unique advantages in terms of controllability and expandability of functional nanomaterials. However, the enormous significance of the cross-scale collaboration of this twins-tech has not aroused widespread recognition and attention in the research community. Here, we first review the development history of E-spinning and E-spraying technologies and clarify how they move from unity to fragmentation. Then, according to the different forms of cooperation, EES is mainly divided into three categories: E-spinning before E-spraying, alternate E-spinning/E-spraying, and simultaneous E-spinning/E-spraying. Next, we summarize the development, application, and challenges of the EES in four different main areas, namely natural environment, energy utilization, human health, and functional membrane regulation. Finally, the challenges, bottlenecks, and development prospects of EES technology in all fields are highlighted, summarized, and discussed from a future perspective.