In this paper, an event-triggered controller based on integral disturbance observer (IDO) and prescribed performance control (PPC) theory is proposed to maintain the trajectory tracking of dynamic positioning vessels (DPVs). A second-order prescribed performance function is designed to better realize error constraint effect. Then, the ETC scheme is designed to complete the task of trajectory tracking subject external disturbances, which can not only ensure tracking performance, but also solve limited communication resources. Finally, a simulation case of comparison is carried out to verify the effectiveness of proposed controller.