This　paper　explores　event-triggered　model　predictive　control　(MPC)　for　constrained　switched　systems,　incorporating　a　buffer-based　anti-attack　(BBAA)　approach　to　ensure　network　security.　Since　the　system　state　is　unknown　and　disturbed,　an　observer-based　$　H_{\infty　}　$　H　infinity　MPC　approach　is　used　to　estimate　the　system　state　and　suppress　disturbance.　Furthermore,　the　estimated　state　and　control　input　can　be　optimised　by　minimising　the　performance　function.　Considering　that　the　system　state　is　subject　to　denial　of　service　(DoS)　attacks　in　the　feedback　channel,　the　BBAA　approach　is　used　to　reconstruct　the　estimated　state,　thereby　reducing　the　impact　of　attacks　on　system　performance.　To　improve　the　utilisation　of　network　resources,　a　set　of　event-triggering　mechanisms　(ETMs)　is　used.　In　addition,　a　set　of　matrix　inequality　conditions　is　given　to　constrain　the　gains　of　controllers　and　observers.　Then,　the　system　$　H_{\infty　}　$　H　infinity　performance　is　demonstrated　by　applying　the　average　dwell　time　(ADT)　and　the　Lyapunov　function　method,　and　the　complex　coupling　between　model　switching,　DoS　attacks　and　event-triggering　is　analysed.　Simulation　results　validate　the　effectiveness　of　the　proposed　approach.