Currently the evaluation of well blowout is mainly about the evaluation of human factors, well control equipment factors and comprehensive factors. These factors include some subjective factors and cannot fully reflect the risk of drilling blowout objectively. In order to reduce the chance of wellflow and prevent well blowout accident that gets out of control in oilfield X, considering the statistical data of geological environment factors that objectively influence the drilling blowout, a model of evaluating drilling blowout risk to oilfield X drilling based on fuzzy mathematics is established. The drilling blowout risk level of each wellblock in oilfield X area has been ranked, and the result indicates that both the wellblock A and the wellblock B are the highest drilling blowout risk areas. The exploratory and development areas in oilfield X are also far away from the Material Supply Centers. In order to save the cost, it should take different well control measures for different risk wellblocks. This paper suggests that the well control ranking management should be implemented in the oilfield X. Various well control measures should be made according to different drilling blowout risk, and the risk ranking of drilling blowout should be included in well control design.