Halide perovskite nanocrystals are potential catalysts for CO₂ photoreduction, while, the strong radiative recombination and insufficient stability limit their catalytic performance and application. Herein, we report that layered double hydroxide nanosheets activate CsPbBr₃ nanocrystals (CLDH) for enhanced photocatalytic CO₂ reduction. These CLDH heterojunctions show the remarkably enhanced CO₂ photoreduction performance; without cocatalyst and sacrificial agent, the average electron consumption rate of CLDH (49.16 μmol·g⁻¹·h⁻¹) is approximately 3.7 times higher than that of pristine CsPbBr₃. Also, CLDH catalyst exhibits a robust stability after ten cycles over 30 h.