Abstract: As the material economy continues to develop, frugality is constantly endowed with new significance in the modern era. As one of the traditional virtues of the Chinese nation, frugality has enjoyed a good reputation. However, does the outcome resulting from frugality always align with ethics? This article attempts to systematically answer this question, revealing the dual-edged effects of frugality on prosocial behaviors from both positive aspects (e.g., enhancing self-control, strengthening social connection, and increasing willingness to cooperate) and negative aspects (e.g., increasing self-interest and cost considerations and reducing perceptions of human nature). The occurrence of these effects can be explained from perspectives such as the theory of resource conservation, self-control theory, life history theory, self-determination theory, social exchange theory, opportunity cost theory, and limited attention theory. There are several directions worth exploring in terms of this topic. Future research could further clarify and develop the moral implications of frugality, conduct cross-cultural studies on the aftereffects of frugality, identify the common role of frugality in different types of prosocial behaviors, explore a theoretical framework and boundary conditions for the unified dual-edged effects, and verify the explanatory role of moral emotions (e.g., gratitude) as psychological mechanisms. These endeavors will promote the integration and development of frugality psychology and prosocial behavior research.