The　proposed　method　is　based　on　the　near-field　fiber　end-face　scanning　of　the　optical　waveguide　mode　field　diameter　measurement　method.　Using　the　scanning　fiber　probe　to　scan　the　optical　waveguide　end-face　Y　direction　and　Z　direction,　to　obtain　the　coupling　efficiency　distribution　of　the　corresponding　direction.　Combining　the　mode　field　distribution　function　and　relative　motion　of　the　fiber　probe　and　the　optical　waveguide,　the　scanning　process　is　modeled　mathematically.　The　relationship　between　the　Gaussian　distribution　of　the　coupling　efficiency　curve　and　the　mode　field　distribution　of　the　optical　wave　is　deduced.　The　mode　field　diameter　of　the　optical　waveguide　can　be　inverse　calculated　accordingly,　and　the　arbitrary　mode　field　distribution　characteristics　can　be　obtained　by　deconvolution　method.　A　near-field　optical　waveguide　mode　field　measurement　system　was　built　to　measure　the　coupling　efficiency　and　dislocation　relationship　between　fiber　and　fiber,　fiber　and　waveguide.　And　accordingly　giving　the　mode　field　diameters　in　the　Y　and　Z　directions　of　the　optical　waveguide　mode　field.　The　feasibility　and　validity　of　the　optical　waveguide　mode　field　diameter　measurement　method　based　on　near-field　fiber　end-face　scanning　are　experimentally　verified.　　©　2022　IEEE.