It is well known that puerarin attenuates ischemia–reperfusion injury and promotes function recovery of ischemic region. However, due to its reverse physiochemical properties, puerarin does not easily cross the blood–brain barrier. The aim of the present study is to create puerarin nanoparticles which increase and prolong the puerarin concentration in the brain. Using emulsion solvent evaporation techniques, we designed puerarin-loaded poly(d,l-lactic-co-glycolic acid) nanoparticles. Hydroxypropyl beta cyclodextrin (HP-β-CD) was used to increase the solubility of puerarin and gelatin to enhance viscosity of inner water phase, which improved puerarin entrapment. The drug release kinetics and nanoparticle degradation in phosphate buffered saline (PBS) were analyzed by electronic microscopy and high-performance liquid chromatography. Computerized tomography scans were used to detect the infarction volume and electroencephalogram (EEG) was recorded to estimate the recovery of brain function. The results showed that the combined HP-β-CD and gelatin significantly improved the entrapment efficiency. The infarction volume was significantly decreased on days 3 and 7 after the administration of puerarin nanoparticles compared with that of control and pure puerarin. EEG was also significantly improved. Puerarin nanoparticles are potentially applicable for the brain injury induced by ischemic–reperfusion.