The prevailing literature has extensively explored the economic ramifications of land reallocation; however, its impact on commons governance remains underexamined. This study, using the agricultural irrigation system in rural China as an example, empirically investigated how land reallocation affects collective action. Survey information from 6298 households, spread across 461 villages in 20 Chinese provinces, served as the basis for the analysis. Our findings suggest that land reallocation is unfavorable for irrigation collective action, but the presence of informal organizations and effective leadership within the village can help ameliorate these negative effects. This research contributes to a more comprehensive understanding of the nexus between land reallocation and irrigation collective action, offering potentially valuable policy insights for countries or regions worldwide that grapple with land reallocation issues.