The basic principle of predicting vapor cloud explosion overpressure by BP neural network was discussed.The influencing factors of overpressure were analyzed emphatically.Based on this,a network model between overpressure and its influencing factors was established after a training process with 80 experimental data groups.Using this model,prediction was conducted for other 20 data groups.The results show the model is basically capable of formulating the relationship between overpressure and its influencing factors.It is an effective means for the predicting vapor cloud explosion overpressure.It is of certain practical significance and applicative value in engineering.