Abstract: With the development of ship upsizing, the mooring safety of LNG carriers has been widely concerned. In order to study the mooring state of LNG ships under different working conditions, this paper establishes the mooring simulation model of Qingdao LNG ship terminal by using the hydrodynamic software AQWA on the basis of the ship motion model, and studies the amplitude response operator of LNG ships with six degrees of freedom under frequency domain analysis. In the time domain analysis, the influence of traditional cable mooring and pre-tension cable mooring on ship mooring dynamic response under different sea conditions is compared. The results show that given a certain initial tension of the cable can effectively restrain the ship’s motion response in the direction of rolling, pitching, yawing, etc., and improve the stability of the mooring. In a certain range, 50 t pretension has a better inhibiting effect on ship motion than 30T pretension, and the effect becomes more obvious with the increase of environmental load. The research result provides technical reference for guiding ship docking, dock mooring design and mooring safety control.