In　this　study,　drainage-induced　displacement　grouting　technology　is　proposed　to　address　directional-induced　grouting　in　saturated　confined　water　sand　layers.　Based　on　Darcy′s　law　and　the　law　of　conservation　of　mass,　the　spatial　distribution　equation　of　the　seepage　pressure　gradient　under　drainage-induced　displacement　grouting　is　deduced.　The　saturated　sand　directional-induced　grouting　experiment　is　used　to　analyze　and　verify　the　results.　The　results　show　the　following.　(1)　Because　the　grouting　and　drainage　pressures　imultaneously　act　on　the　seepage　field,　the　seepage　pressure　gradient′s　space　distribution　curve　shows　a　law　of　decreasing　first,　then　increasing.　The　directional-induced　seepage　grouting　can　be　realized　when　the　lowest　point　of　the　seepage　pressure　gradient′s　spatial　distribution　curve　is　greater　than　the　starting　gradient.　(2)　The　theoretical　derivation　formula　can　reflect　the　seepage　pressure　gradient　distribution　under　drainage-induced　displacement　grouting　to　a　certain　extent.　The　theoretical　formula　calculation　results　agree　well　with　the　model　experimental　results.　(3)　After　the　seepage　pressure　gradient　becomes　stable,　the　error　between　theoretical　and　experimental　values　is　between　4.4%　and　29.0%.　The　theoretical　calculation　data　are　all　small,　and　the　error　is　acceptable.　(4)　The　drainage-induced　displacement　grouting　can　induce　the　directional　diffusion　of　grout　to　a　certain　extent,　forming　the　expected　directional　reinforcement　area　in　the　saturated　confined　water　sand　layer.　According　to　existing　grouting　construction　experiences　and　experimental　research,　the　maximum　spacing　of　drainage-induced　displacement　grouting　should　be　controlled　between　50　and　90　cm.　©　2022,　Editorial　Office　of　Tunnel　Construction.　All　rights　reserved.