Background: Laohekou New Year Pictures, dating back to the Ming and Qing Dynasties, is an important art in southern China. Due to development and inheritance crises in the 21st century, more social co-creation and social resources are needed to participate in the protection and inheritance of Laohekou New Year Pictures to promote their further sustainable development. Purpose: Protecting Laohekou New Year Pictures is full of prosocial behaviors, which is significant for developing these Pictures. This study analyzes the protection of Laohekou New Year Pictures based on the theory of prosocial behavior in social psychology. Methods: The protection behavior of Laohekou New Year Pictures was analyzed based on the theory of prosocial behavior, voluntarism, prosociality, and altruism. The four factors affecting the protection behavior were discussed, and relevant protection strategies were provided for future development. Results: This paper analyzes the characteristics and influencing factors of prosocial behavior of Laohekou New Year Pictures. It presents four strategies: "reducing the ambiguity of public responsibility participation", "giving full play to the driving force of opinion leaders", "strengthening the mechanism and system construction of rewards and punishments", and "skills popularization of New Year Picture heritage education". Conclusion: This paper combines the prosocial theory of social psychology with the intangible cultural heritage protection theory to conduct an interdisciplinary study. This study focuses on the four aspects of protection nature, protection subject, protection result and protection behavior embodied by the prosociality of Laohekou New Year Pictures. This makes the protection behavior of Laohekou New Year Pictures reflect the characteristics and influencing factors of prosocial behavior, and the related protection research permeates intangible prosocial behavior, which provides strategic guidance for the protection of intangible cultural heritage, provides future social support of altruism and public welfare for heritage inheritance, and further promotes the long-term development of Laohekou New Year Pictures.