The issue of sustainability has once again received attention and promotion in the post-COVID-19 pandemic era. Countries worldwide have launched returnable cup services for beverages, such as Taiwan, which is a highly developed market for hand-shaken drinks, and various beverage and convenience stores have been gradually launching this service. However, reasonable usage rates have yet to be achieved. This study aimed to explore the psychological cognition of using a returnable cups service by understanding the motivation affecting the behavior intention through external and internal influencing and categorizing realistic cognition, which observes the motivating factors from three perspectives: passively acquired awareness, autonomous consciousness, and perception in real life for further achieving environmental sustainability. Research found that when consumers’ environmental awareness is insufficient to sacrifice convenience, it is necessary to employ a service strategy design for passive influence. The focal point for influencing consumer attitudes lies in the backend of services, particularly in cup return, which is the chain-closing juncture. The result can provide the beverage industry and governments with a reference to promote returnable cups and contribute to plastic reduction in sustainable development.