This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.The vessel collision risk in the bridge operation period has become an acute problem that bridge engineering have to be faced, therefore, probability analysis and risk assessment about vessel-bridge collision in the bridge operation period is important. Combine with Zhoushan mainland-islands link project, using the AASHTO guide method and correction formula to calculate the probability about vessel collision with the pier 3 and to assess the risk about vessel-bridge collision of Xihoumen bridge in the operation period. The whole vessel-bridge collision risk assessment grade of Xihoumen bridge is grade two in the operation period, which is a low risk level. The operation manager need to pay attention to risk management and take preventive and control measures.