Flip-flow　vibrating　screens　(FFVSs)　effectively　tackle　the　challenges　posed　by　the　dry　deep-screening　of　wet,　fine,　low-grade　bituminous　coal,　thereby　facilitating　advancements　in　the　thermal　coal　preparation　process.　The　tensile　lengths　of　the　screen　panels　not　only　influence　the　service　lives　of　the　screen　panels　but　also　play　a　pivotal　role　in　determining　the　screening　performance　of　the　FFVSs.　To　investigate　the　effect　of　the　screen-panel　tensile　length　on　the　screening　performance　of　an　FFVS,　this　study　constructs　a　dual-mass　flip-flow　screening　test　rig.　The　experimental　results　reveal　that　when　the　fine-particle　content　and　the　external　water　content　in　the　feed　of　low-grade　bituminous　coal　are　55%　and　16%,　respectively,　the　most　favorable　tensile　length　of　the　screen　panels　is　2　mm.　With　a　fine-particle　content　of　55%　in　the　feed　of　low-grade　bituminous　coal　and　an　increase　in　the　external　water　content　from　4%　to　20%,　the　screening　efficiency　of　the　FFVS　initially　decreases　and　then　increases.　Notably,　low-grade　bituminous　coal　with　16%　external　water　content　poses　the　most　challenging　screening　conditions.　Furthermore,　when　the　external　water　content　of　the　low-grade　bituminous　coal　is　16%　and　the　fine-particle　content　in　the　feed　increases　from　25%　to　55%,　the　screening　efficiency　of　the　FFVS　gradually　improves.