A　significant,　fundamental　challenge　in　the　field　of　valleytronics　is　how　to　generate　and　regulate　valley-polarized　currents　in　practical　ways.　Here,　we　discover　a　new　mechanism　for　producing　valley　polarization　in　a　monolayer　transition　metal　dichalcogenide　superlattice,　in　which　valley-resolved　gaps　are　formed　at　the　supercell　Brillouin　zone　boundaries　and　centers　due　to　intervalley　scattering.　When　the　incident　energy　of　the　electron　lies　in　the　gaps,　the　available　states　are　valley　polarized,　thus　providing　a　valley-polarized　current　from　the　superlattice.　We　show　that　the　direction　and　strength　of　the　valley　polarization　may　be　further　tuned　by　varying　the　potential　applied　to　the　superlattice.　The　transmission　can　have　a　net　valley　polarization　of　55%　for　a　four-period　heterostructure.　Moreover,　two　such　valley　filters　in　series　may　function　as　an　electrostatically　controlled　giant　valleyresistance　device,　representing　a　zero-magnetic　field　counterpart　to　the　familiar　giant　magnetoresistance　device.