Abstract: We investigate the formation control for linear swarm systems with complex communication conditions of time-varying delays and switching interaction topologies. Firstly, we propose a formation control protocol based on consensus theory. Secondly, we transform a formation control problem with the two complex communication conditionsinto the stabilization problem of delay-dependent systems using variable substitution. We construct the common Lyapunov-Krasovskii functional and analyze the stabilization problem of delay-dependent systemsby free-weighting matrices method. Then, the linear matrix inequality (LMI) criterion for large-scale swarm systems with lower conservative is obtained. We also give the upper bounds of delays and the controller gain. Finally, we demonstrate the theoretical results and low conservative by numerical simulations.