To ensure the transportation safety of oversize/overweight（OS/OW） products, the problem of the poor passing capability of pole trailer in turning should be solved. After analysis of the pole trailer’s static structure and dynamic turning characteristics, we deduce the iterative formula of the model’s key points coordinates. The dynamic computer simulation system of the pole trailer’s turning process is developed, which can provide guidance for the pole trailer to pass the crooked road smoothly during transport process.