To　enrich　and　recover　low-concentration　(10　1　-　10　2　ppm)　rare　earth　elements　from　ores　and　industrial　wastes,　high　phase-ratio　solvent　extraction　is　favored.　However,　high　phase-ratio　solvent　extraction　is　limited　by　low　mass　transfer　efficiency　in　the　continuous　phase　due　to　the　insufficient　contact　between　large　volume　continuous　phase　and　sparse　droplets.　To　realize　efficient　solvent　extraction　of　rare　earth　ions　from　low　concentrations　(100　ppm)　aqueous　phase　to　oil　phase　with　high　phase　ratio,　we　introduce　a　type　of　microchannel　with　sequential　pore-throat　geometry.　This　sequential　pore-throat　geometry　creates　capillary　barriers　and　effectively　retains　dispersed　droplets,　leading　to　a　reduction　of　apparent　water　-　oil　volume　ratio　and　thereby　major　mass　transfer　enhancement　in　the　continuous　phase.　We　experimentally　highlight　its　advantage　over　classic　uniform　microchannel　for　solvent　extraction　of　rare　earth　ions　under　high　phase　ratios:　in　a　double　pore-throat　microchannel,　extraction　equilibrium　can　be　reached　within　30　s　under　high　phase　ratios　of　50　-　250;　for　an　extreme　phase　ratio　of　500:1,　extraction　efficiency　can　achieve　77　%　within　a　quadruple　pore-throat　channel,　while　that　within　a　uniform　microchannel　is　only　below　40　%.　The　superiority　of　sequential　pore-throat　microchannel　for　extraction　at　a　high　phase　ratio　is　reproduced　using　different　types　of　rare　earth　ions.　We　thus　conclude　that　sequential　porethroat　geometry　can　drastically　promote　the　performance　of　microfluidic-based　solvent　extraction　at　extreme　phase　ratios,　for　rare　earth　enrichment　and　potentially　for　other　relevant　applications.