The issue of how platform enterprises evolve from being driven primarily by commercial interests to organizations that balance both economic and social missions is a significant topic. Employing Pinduoduo as a longitudinal case study, this paper delves into the dynamic equilibrium between economically and socially value-oriented behaviors during the growth trajectory of platform enterprises, elucidating the dynamic evolution mechanism of their organizational hybridity from an identity perspective. The study finds that platform enterprises, during their startup, growth, and maturity stages, respectively experience a progression from identity void to meaning construction, identity threat driving meaning disruption, and identity opportunity pulling meaning reconstruction. Through the institutional logic coordination mechanism of “meaning generation–meaning assignment”, these enterprises achieve the dynamic evolution of hybrid organizational identity. This process results in the formation of three organizational identity types: profit-seeking and enterprise-building, dual-balanced, and ecology co-benefiting, with their hybridity progressively strengthening. This paper explores the types of hybrid organizational identity in platform enterprises and the iterative mechanism underlying their dynamic evolution, offering new insights into the growth trajectory of platform enterprises that balance both social and economic values. The findings provide practical guidance for platform enterprises at different stages of development, suggesting differentiated identity-building strategies to avoid “social disembedding” and effectively undertake their social missions.