This　article　studies　the　formation　and　trajectory　tracking　control　of　multiagent　systems.　We　present　a　novel　multilayer　graph　for　the　multiagent　system　to　enable　extensibility　of　the　interaction　network.　Based　on　the　multilayer　graph,　a　formation　control　law　by　using　the　potential　function　approach　is　developed　for　autonomous　formation,　formation　maintenance,　collision,　and　obstacle　avoidance.　When　the　desired　formation　is　achieved,　the　barycentric　of　the　formation　shape　is　viewed　as　a　virtual　leader,　and　a　model　predictive　control　(MPC)　scheme　is　applied　to　the　virtual　leader　for　tracking　a　reference　trajectory;　meanwhile,　the　agents　will　maintain　the　desired　angles　and　distances　via　the　formation　control　law.　By　applying　the　proposed　schemes,　the　tasks　of　formation　maintenance　and　trajectory　tracking　in　a　constrained　space　are　fulfilled.　Comprehensive　simulation　studies　under　different　environmental　constraints　and　trajectories　confirm　the　effectiveness　of　the　proposed　approaches　in　addressing　the　formation　and　trajectory　tracking　problems.