The groundwater has been polluted during developing the Fuyu Oil Field. This paper predicted the pollution distance and degree by evaluating and analyzing the status in quo. The influence of the oil field on groundwater environment under normal and accidental production condition was respectively forecasted with numerical simulation. The results show that the transport time of oil infectant in waste water is 5.7 year in quaternary phreatic water and the concerned transport distance is 724.5m when the concentration of oil pollutant is less than or equal to 0.05mg/1 and groundwater quality meets the criterion of grade III. In quaternary confined water, however, the transport time is 9.7 year and distance is 1413.5m. Otherwise, prediction was also made for the effect of pollutant on groundwater after 1, 3, 5 and 10 years under oil accidental condition. The results show that the transport distance of pollutant in quaternary phreatic water is 160.2m, 439.5m, 711.8m and 1381.4m respectively, and the concerned distance is 208.6m, 544.3m, 869.6m and 1656.7m. Finally, the contamination control measures were presented according to the pollution status.