Deployment of buoy systems is one of the most important procedures for the operation of buoy system.In the present study,a single-point mooring buoy system which contains surface buoy,cable segments with components,anchor and so on is modeled by applying multi-body dynamics method.The motion equations are developed in discrete node description and fully Cartesian coordinates.Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board.The trajectories and velocities of different nodes without current and with current in buoy system are obtained.The transient tension force of each part of the cable is analyzed in the process of deployment.Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration.This work is helpful for design and deployment planning of buoy system.