Soleplates of special automobile produced by thermoforming were investigated through numerical simulation and thermoforming experimentation and the soleplates were manufactured by once forming. The results show that the dies and processing parameters are appropriate, and the positions in which the forming property is low (such as corner angles and flanging parts at the ends) are processed perfectly. The soleplates could be produced by once forming through optimizing the dimension of sheets, and not less than 15 soleplates with excellent properties could be produced in one hour. The batch production of the soleplates could be achieved for the high production efficiency.