In order to analyze the effect of zeolitic imidazolate framework（ZIF）nanoparticles as nano-oil flooding agent on enhanced oil recovery，ZIF-8 nanoparticles were prepared at ambient temperature and aqueous phase using zinc nitrate hexahydrate and 2-methylimidazole as original materials. The microstructure of ZIF-8 nanoparticles was characterized. ZIF-8 nanoparticles were dispersed in water to obtain nanofluid. The stability of the nanofluid was studied，and the mechanism of enhanced oil recovery was analyzed by measuring oil-water interfacial tension and contact angle. Finally，the oil displacement efficiency of ZIF-8 oil displacement system was evaluated through core displacement experiment. The results showed that the average diameter of ZIF-8 nanoparticle was 65.8 nm，and the phase state was single without impurity. When the mass fraction was not higher than 0.03%，the dispersion of ZIF-8 nanoparticle in water was excellent，and the absolute value of Zeta potential was about 30 mV，indicating a high stability. After adding 0.03% ZIF-8 nanoparticle to simulated formation water and low salinity water，the oil-water interfacial tension decreased to 4.66 and 3.97 mN/m，respectively，which decreased by 75.77% and 73.25% compared with that without adding. The contact angle between nanofluid and core slice decreased from 114° and 109° to 78° and 73°，respectively，and the rock surface turned to water-wet，which was more conducive to the peeling of oil film. In the core displacement experiment，after flooding with formation water until oil-free production，0.03% ZIF-8 nanofluid was injected. The recovery factor in formation water and low salinity water was increased by 8.25 percentage points and 10.7 percentage points，respectively，which showed a good effect of enhanced oil recovery.