Abstract: Five strains of separated oil-degrading bacteria and their compound preparations were used to study their remediation effects on oil-contaminated soil by laboratory simulation and field repair. After treated with compound preparations for 48 days, the oil-degrading rate was above 84%, obviously higher than that treated with single strain. The biodegradability of all strains was in the order of H>A6>F2>A5>D4>F1. The oil-degrading rate increased sharply near 10 days, but gradually slowed down after 20 days. The dehydrogenase activity of compound preparations was higher than that of single strain. There existed significant correlations between the microbial population size, dehydrogenase activity, and oil-degrading rate. With the time changed, the oil-based compounds, saturated hydrocarbons, and aromatic hydrocarbons had obvious degradation, among which, saturated hydrocarbon had the fastest degradation rate, while nonhydrocarbon and asphaltene had the slowest one.