Combined with the backstepping technique, a neural network (NN)-based adaptive tracking control scheme is proposed for the Accommodation Vessel (AV). The control objective is to steer AV following the trajectory of Floating Production Storage and Offloading (FPSO) and keeping the desired distance with FPSO so that the smooth gangway operation can be achieved. In order to fulfill the control task, backstepping is used to achieve the tracking of trajectory; adaptive neural network is used to approximate the unknown nonlinear dynamic of AV for controller design. Finally, it is proven that the proposed control approach can guarantee AV following to FPSO. The simulation results further demonstrate effectiveness of the proposed method.