To investigate the residual levels of polycyclic aromatic hydrocarbons (PAHs) in topsoil and corns in the Yellow River Delta oil extraction area, total 71 samples of farmland soils and 71 samples of corns were collected. The content of 16 PAHs in soils and spinach were detected. The Nemerow pollution index method and the health risk assessment model were used to assess the ecological health risks of PAHs in farmland soil. The results showed that the contents of PAHs in farmland soil, corn roots, stems, and leaves were 256.6-1936 μg/kg, 291.4-680.9 μg/kg, 324.9-527.9 μg/kg, and 289.5-2400 μg/kg, respectively. The results showed that PAHs in farmland soils were dominated by 4-6 rings. The order of PAHs enrichment coefficients in root, stem and leaf was leaf > stem > root. The correlation analysis results of the PAHs concentration in different corn tissues and the PAHs concentration in the corresponding farmland soil showed that there was very significantly positive correlation between the PAHs content in the farmland soil and the PAHs content in the corn root and stem, and the correlation coefficients were 0.98 (P<0.01), 0.98 (P<0.01), respectively. It indicates that the PAHs of corn roots and stems are mainly from farmland soil, and the content of PAHs in farmland soil affects the accumulation and distribution of PAHs in corn roots and stems. There is no correlation between PAHs content in corn leaves and PAHs content in farmland soil and PAHs content in corn roots and stems, which indicating that PAHs in corn leaves do not come from the migration of PAHs in soil, but may come from the atmosphere. The Nemerow index results showed that the PAHs in farmland soils have reached moderate pollution, and BaA, Pyr, and BbF have reached heavy pollution. The health risk assessment results showed that the average non-carcinogenic risk of PAHs in farmland soils to children and adults was 0.44<1, 0.12 <1, indicating that the non-carcinogenic risk of PAHs in farmland soils is acceptable for adults and children. The average carcinogenic risk of PAHs in farmland soils for children and adults was 3.6×10^-5 and 9.0×10^-6, respectively, which was less than the upper limit of acceptable cancer risk of 10^-4. Among the three exposure routes, skin contact is the most important way of exposure to soil PAHs, followed by oral ingestion, and the inhalation exposure route is negligible. The risk of PAHs to children's health is greater than that of adults, so it is necessary to avoid children's direct contact with or ingestion of soil and other pollutants by mistake.