In order to solve the problems of collision, communication interruption and external disturbances during formation forming of Multi-Agent Systems (MASs), the robust formation control with collision avoidance and connection preservation for nonlinear second-order MASs is studied.Based on the Artificial Potential Field (APF) method, the collision avoidance algorithm is designed, which can maintain connections among agents, and distributed control law and consensus theory are employed to design the robust formation control law of the MASs, so that accurate formation forming with collision avoidance and connection preservation of the MASs is realized.Lyapunov stability theory and Linear Matrix Inequality (LMI) are used to guarantee the stability of the MASs and the convergence of tracking errors.The effectiveness of the proposed formation control law is demonstrated by numerical simulations.