Side-chain　fluorination　can　enhance　the　backbone　organization　and　carrier　mobility　of　non-fullerene　acceptors　(NFAs)　but　it　often　reduces　their　photovoltage　due　to　the　resulting　deeper-lying　lowest　unoccupied　molecular　orbital　(LUMO)　levels.　Herein,　we　present　a　strategy　to　regulate　the　LUMO　levels　of　two　NFAs,　MC9F5　and　MC7F5,　by　repositioning　the　highly　electronegative　-C2F5　moieties　on　the　side　chains.　This　approach　mitigates　the　impact　of　fluorination　on　the　energy　levels,　thereby　improving　the　photovoltage　and　overall　device　performance.　By　incorporating　10,10,11,11,11-pentafluoro-2-(8,8,9,9,9-pentafluorononyl)undecyl　side　chains,　the　-C2F5　moieties　are　positioned　away　from　the　conjugated　backbone　of　MC9F5,　resulting　in　an　elevated　LUMO　level　compared　with　MC7F5,　which　features　8,8,9,9,9-pentafluoro-2-(6,6,7,7,7-pentafluoroheptyl)nonyl　side　chains.　This　modification　reduces　both　the　charge　generation　and　the　non-radiative　energy　losses　in　the　MC9F5-based　devices.　The　MC9F5-based　small-area　and　minimodule　devices　achieve　efficiencies　of　18.02%　and　15.66%,　respectively,　which　are　among　the　highest　values　reported　for　acceptor-donor-acceptor-type　NFAs.　This　study　highlights　a　valuable　fluorination　strategy　for　achieving　high-performance　NFAs.　By　strategically　relocating　the　electronegative　-C2F5　groups　on　side-chains　of　M-series　acceptors,　we　developed　an　effective　approach　to　precisely　modulate　their　energy　levels　thereby　enhancing　photovoltage　and　overall　device　performance.