Based on the plastic bending theory, the influence of material properties fluctuations of pipeline steel on the air bending is discussed by the computer simulation technology and design of the orthogonal was adopted to define scientific simulation experiment scheme. Among the material properties, initial yield strength is the most critical issue. The relation of the initial yield strength, the key process parameter, punch penetration, and the tube forming quality was studied and the variation of bending angle after springback and forming force with the punch insertion was analyzed. The parameters prediction model, which was established by using RBF network technology, is proved rational and precise since the error between predicting results and simulation value is very small. The method can be used to optimize the relevant process parameters and to design the reasonable process scheme.