The　reinforcing　and　restraining　effect　of　piles　embedded　in　soils　is　objective　existence.　However,　the　correlative　research　work　on　pile　groups　settlement　methods　is　not　deep　enough　and　needs　to　be　continued.　Based　on　the　shear　displacement　method,　considering　the　reinforcing　and　restraining　effect,　the　settlements　of　the　analyzing　pile　caused　by　loads　on　the　pile　top　were　calculated,　including　the　reduction　effect　caused　by　the　existence　of　the　other　adjacent　piles.　And　the　additional　settlements　of　the　adjacent　piles　arising　from　the　settlement　of　the　loaded　pile　were　obtained　as　well.　Thus　a　simplified　formula　of　interaction　coefficients　between　any　two　piles　was　presented.　Meanwhile,　the　equivalent　shear　stiffness　coefficients　of　soil　around　each　pile　were　developed;　and　an　equation　of　displacements　caused　by　load　on　top　of　the　analyzing　pile　imbedded　in　multi-layered　soils　was　built;　so　recurrence　relations　of　settlement　and　axial　force　of　pile　shaft　between　upper　and　lower　of　each　pile　sections　were　respectively　deduced;　in　the　process　of　deduction,　Boussinesq　solution　was　modified　to　include　the　effect　of　different　embedded　depths,　and　then　used　to　derive　the　equivalent　stiffness　coefficients　of　the　soil　under　the　pile　tips.　Lastly,　the　formula　was　extended　to　the　settlements　calculation　of　high　and　low　cap　pile　groups.　Different　methods　were　compared　with　two　engineering　cases.　The　results　show　that　the　load-settlement　curve　computed　by　present　method　agreed　well　with　those　measured　from　real　engineering　cases;　and　the　calculating　interaction　coefficients　are　much　less　than　ones　calculated　by　the　elastic　theory　method.