The　valorization　of　manufactured　sand　tailings　(MST)　with　annual　production　of　4　billion　tons　is　crucial　to　the　healthy　development　of　manufactured　sand　industry.　The　feasibility　of　compacted　MST–bentonite　mixtures　as　hydraulic　barrier　in　landfill　cover　system　was　studied　herein.　A　series　of　rigid-wall　permeation　tests　were　carried　out　to　measure　the　saturated　hydraulic　conductivity　(ks)　of　compacted　MST–bentonite　specimens,　considering　bentonite　content,　mixing　method,　sieving　treatment,　and　degree　of　compaction　(DOC).　The　ks　of　specimens　prepared　by　different　methods　were　listed　as　follows:　without　water　<　water　pouring　<　gradual　water　addition.　It　was　because　the　specimen　prepared　without　water　had　a　unimodal　pore-size　distribution　and　had　the　least　macro-pores,　while　the　specimens　prepared　by　the　other　two　methods　had　bimodal　pore-size　distributions.　Sieving　helped　reduce　the　ks,　due　to　less　macro-pores.　The　effect　of　sieving　on　ks　decreased　at　higher　DOC.　The　decrease　of　ks　was　more　significant　with　the　increase　of　bentonite　content　at　lower　DOC.　Accordingly,　it　is　suggested　to　mix　MST　with　10%　bentonite　and　then　compacted　without　water　at　DOC　no　less　than　90%,　so　that　the　allowable　ks　of　10–9 m/s　required　by　design　guideline　of　hydraulic　barrier　of　landfill　cover　can　be　met.　©　2022,　Springer　Japan　KK,　part　of　Springer　Nature.