In　this　paper,　we　study　the　well-posedness　theory　of　the　magneto-micropolar　boundary　layer　and　justify　the　high　Reynolds　numbers　limit　for　the　magneto-micropolar　system　with　Prandtl　boundary　layer　expansion.　If　the　initial　tangential　magnetic　field　is　nondegenerate,　we　obtain　the　local-in-time　existence,　uniqueness　of　solutions　for　the　incompressible　magneto-micropolar　boundary　layer　equations　with　the　lower　regularity　initial　data　in　H3\documentclass[12pt]{minimal}　\usepackage{amsmath}　\usepackage{wasysym}　\usepackage{amsfonts}　\usepackage{amssymb}　\usepackage{amsbsy}　\usepackage{mathrsfs}　\usepackage{upgreek}　\setlength{\oddsidemargin}{-69pt}　\begin{document}$$H_3$$\end{document}.　This　work　is　inspired　by　the　recent　progresses　by　Liu　et　al.　(Commun　Pure　Appl　Math　72(1):63-121,　2019)　for　2D　MHD　boundary　layer　equations　theory　in　Sobolev　spaces　without　monotonicity.　There　are　some　differences　between　this　work　and　Liu　et　al.　(2019).　First,　the　model　has　the　familar　form　of　the　MHD　equations　but　it　coupled　with　the　equation　of　the　microrotation　field,　which　essentially　describes　the　motion　inside　the　macrovolume　as　they　undergo　mocro-rotational　effects　represented　by　the　micro-rotational　velocity　vector.　Second,　the　lack　of　higher-order　boundary　condition　at　y=0\documentclass[12pt]{minimal}　\usepackage{amsmath}　\usepackage{wasysym}　\usepackage{amsfonts}　\usepackage{amssymb}　\usepackage{amsbsy}　\usepackage{mathrsfs}　\usepackage{upgreek}　\setlength{\oddsidemargin}{-69pt}　\begin{document}$$y=0$$\end{document}　is　one　of　the　main　difficulties　to　solve　the　Prandtl　type　equations.　We　present　a　reconstruction　argument　for　higher-order　boundary　conditions　to　fix　this　technical　difficulty.　Third,　our　greatest　difference　is　the　application　of　a　stratified　energy　estimates　instead　of　using　space-time　differential　multi-indices　as　in　Liu　et　al.　(2019),　so　we　can　work　in　a　functional　framework　of　lower　regularity.　Our　analysis　is　based　on　direct　Sobolev　spaces　and　allows　us　to　give　an　L　infinity\documentclass[12pt]{minimal}　\usepackage{amsmath}　\usepackage{wasysym}　\usepackage{amsfonts}　\usepackage{amssymb}　\usepackage{amsbsy}　\usepackage{mathrsfs}　\usepackage{upgreek}　\setlength{\oddsidemargin}{-69pt}　\begin{document}$$L＜^＞\infty　$$\end{document}　estimate　on　the　error　by　multiscale　analysis　under　the　assumption　that　the　kinematic,　spin　viscosity　coefficients　and　the　resistivity　coefficient　are　of　the　same　order　and　the　initial　tangential　magnetic　field　on　the　boundary　is　not　degenerate.