To Multi-robot control problems, this paper based on Leader — Follower dynamic model, uses linearization technique to design velocity controller for transforming the nonlinear system into a linear system, the formation control problem is transformed into robot tracking problem, with feedback relative distance and angle between Follower and Leader to control velocity. In the moving process to target point, the shape of formation should be maintained, but for avoid obstacle the whole formation can shrink or amplify in scale, or change the leader temporary. The Matlab7.8.0 simulation result indicated the method can reduce the control complexity, possess better robustness and stability in proceeding formation control problem.