Chaotic　oscillation　is　a　harmful　phenomenon　for　power　system　and　it　threatens　the　safe　and　stable　operation　of　power　system.　This　paper　presents　fractional　order　fixed-time　nonsingular　terminal　sliding　mode　control　to　suppress　chaos　in　power　system.　A　novel　fractional　order　terminal　sliding　mode　surface　is　first　proposed　to　guarantee　the　fixed-time　convergence　of　system　states　along　the　sliding　surface,　and　then　a　nonsingular　terminal　sliding　mode　controller　is　designed　to　force　the　system　states　to　reach　the　sliding　surface　within　fixed-time　and　stay　on　it　forever.　Furthermore,　the　fixed-time　stability　and　the　robustness　of　the　proposed　control　scheme　are　proved　using　the　fractional　Lyapunov　stability　theory.　Finally,　the　proposed　control　scheme　is　applied　to　suppress　chaos　in　fractional　order　power　system　and　simulation　results　demonstrate　the　effectiveness　of　the　proposed　control　scheme.