Objective To investigate the influence of curcumin on the Notch2/Hes-1 pathway after pulmonary injury induction via limb ischemia–reperfusion (I/R). Methods Adult male Sprague–Dawley rats were randomly divided into four groups (n = 30 each): sham, I/R, curcumin post-treatment (I/R+Cur), and inhibitor (I/R+DAPT). Hind-limb ischemia was induced for 4 hours, followed by reperfusion for 4 hours. After ischemia, curcumin (200 mg/kg) or DAPT (0.5 µm) was injected intraperitoneally in the I/R+Cur or I/R+DAPT group, respectively. PaO2 was examined after 4 hours of reperfusion. Pathological changes in the lung and the apoptotic index (AI) were examined. Lung malondialdehyde (MDA), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β levels, the wet/dry (W/D) ratio, semi-quantitative score of lung injury (SSLI), and Notch2 protein and Hes-1 mRNA expression were also examined. Results In the I/R group, inflammatory changes were observed, AI increased, and MDA, SSLI, W/D, TNF-α, IL-1β, Notch2, and Hes1-mRNA expression increased, while PaO2 decreased compared with the Sham group. Pathological changes in the I/R+Cur group were reversed. All indexes in the I/R+DAPT and I/R+Cur group were similar. Conclusion Curcumin post-treatment reduced I/R-induced lung injury in rats. Its mechanism may be related to the inhibition of Notch2/Hes-1 signaling pathway and the release of inflammatory factors.