Abstract: The obstacle avoidance of a single mobile robot is solved by using stream function,and a multiple mobile robots swarming control model with a virtual leader and bintree structure is presented,which is based on stream function and singular association(SA) rule.The bintree structure based on SA rule makes it more flexible and simple to control the robots swarm.By introducing the virtual leader, the swarm wouldn't be separated during obstacle avoidance,and the situation that some robots drop behind can be solved very well.This improves the stability and flexibility of the system.Simulations are presented to demonstrate the validity of the model.