Since the multimedia device plugs are complex and variety, a three-dimensional simulation method of connector behavior is proposed in this paper. Based on the collision detection system in Unity3D, the interaction between the connector and the interface is realized. The users’ operation is limited in two-dimensional plane by a trick of special collision detector setting. The efficiency and accuracy is boosted when third dimension motion of connector is controlled. The Coroutine in MonoBehaviour is used for improving the reality of the system. Simulation results show that this method has merits of verisimilitude, easy to implement, good user experience and strong portability.