Using data from Chinese listed platform enterprises between 2008 and 2023, this study employs a multi-period DID (difference-in-differences) approach to assess the impact of platform enterprise mergers and acquisitions (M&As) on labor income share. The results show that platform enterprise M&As significantly reduce labor income share through three channels: enhancing market power, driving technological progress, and fostering the gig economy. Heterogeneity analysis indicates that the negative impact of platform enterprise M&As on labor income share is more pronounced in firms with high financing constraints, in high-tech industries, and in regions with weaker labor protection. Further analysis reveals that platform enterprise M&As increase the labor income share of high-skilled workers while squeezing the labor income share of low-skilled workers. Additionally, the impact of platform enterprise M&As on labor income share is related to the scale of the merger, with larger merger scales significantly reducing the labor income share of firms.