Open innovation communities are increasingly becoming an important external source for companies to acquire ideas, so it is increasingly important to study the mechanisms that motivate community users to participate in community content creation. Based on the "stimulus-organism-response" theoretical framework, this study constructed a chain mediation model in which internal and external incentives influenced user innovation behavior through basic psychological needs and harmonious passions, and explored the boundary role of external incentives. The data was analyzed by using Bootstrap and hierarchical regression method. The results show a "crowding" effect between internal and external incentives, that is, external incentives negatively regulate the influence of internal incentives on users" basic psychological needs. Both the satisfaction of basic psychological needs and harmonious passion play a mediating role in influencing internal and external incentives on user innovation behavior. In addition, Internal and external incentives influence user innovation behavior through the chain mediating effects of the basic psychological needs and harmonious passion.? This study further clarifies the mechanism of internal and external incentives on user innovation behavior, and provides reference implications for guiding the construction of community motivation mechanism.