The rational allocation of authority across government levels is crucial for the effective provision of environmental public goods. Based on China’s environmental policy texts (1973–2023) and case studies, this paper analyzes the division and adjustment of environmental governance powers. The findings reveal selective decentralization under the trend of centralization over the past fifty years in China’s environmental governance: (1) Legislative power has been conditionally devolved, to encourage distinctive local environmental legislation that is non-contradictory to central legislation; (2) Administrative power has transitioned from an ambiguous two-tier system to a three-category framework with attempts to quantify shared authorities. This recentralization aligns with the principle that national public goods are provided by the central government, while regional ones are supplied jointly; (3) Supervisory power has transitioned from local to vertical management, and its oversight has been elevated to a national initiative, receiving strong political endorsement.