Pseudo-halide　substitution　is　an　effective　approach　to　enhance　the　performance　and　stability　of　perovskite　optoelectronic　devices.　However,　the　role　of　pseudo-halide　ions　played　in　the　perovskite　light-emitting　diodes　(PeLEDs)　is　still　rarely　investigated.　Herein,　we　have　synthesized　the　organic　salt　PEABF(4)　(PEA　=　phenylethylamine)　as　a　pseudo　halide　substitute　for　surface　halides　in　PEABr　and　fabricate　quasi　two-dimensional　(quasi-2D)　PeLEDs.　The　incorporation　of　BF4-　anion　improves　the　photoluminescence　(PL)　intensity　and　lifetime　by　taking　advantage　of　improved　crystallinity　and　enlarged　grain　size.　The　BF4　substituted　PeLEDs　shows　great　improvement　of　performance　to　the　control　devices.　The　optimized　device　with　structure　of　indium　tin　oxide-coated　glass　(ITO(glass))/poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)(PEDOT:PSS)/perovskite/　4,7-Diphenyl-1,10-phenanthroline　(Bphen)/Ag　produces　a　maximum　luminance　at　44850　cd/m(2),　and　an　efficiency　of　11.5　cd/A,　respectively.　Through　further　investigation　by　optical　and　electrical　characterization,　we　find　the　substitution　of　BF4-　anion　has　merits　on　the　enhancement　of　exciton　binding　energy　and　suppression　of　non-radiative　trap-assisted　recombination　on　the　surface.　These　results　provide　better　understanding　of　pseudohalide＇s　benefits　in　perovskite　light-emitting　devices.