Abstract: Aiming at the problems of high risk, high operation cost and limitation of the time, space and number for semi-physical navigation simulator experiments in ship coordinating collision avoidance experiment, combined with the actual situation of ship coordinating avoidance experiment teaching, the 3D online virtual simulation experiment teaching platform for ship coordinating avoidance is developed by using Unity3D engine. The platform has three functions including independent learning, simulation training and learning effect detection. According to the actual work on board, the experimental teaching scheme of ship coordinating avoidance is designed. And its operational effect on the platform is displayed, which proved the effectiveness of the platform. The autonomous and exploratory experiments of ship coordinating avoidance are carried out through the platform, which overcomes the shortcomings of real ship experiment and navigational simulator experiment, changes the traditional experimental mode, improves the experimental teaching effect and enhances students' interest in learning.