In the teaching of suspension bridge, the main cable saddle and the relative position of the tower, cable saddle preliminary deviator, cable saddle pushing principle understanding are difficult. The structure chart for the relative position of the saddle and the tower should be appropriately complemented, and the relative position and preliminary deviator calculation formula were deduced. The main rope saddle line and the center line of the main tower generally are not coincidence, preliminary deviator is to point out an empty line state to ensure the main tower vertical and set the rope saddle offset, and jacking times and pushing quantity can be adjusted. It enriched the content of the teaching material which can help students understand this part and improve their learning interest of the suspension bridge.