Melt　electrospinning　writing　is　a　new　and　promising　method　for　fabricating　micro/nanofibers,　which　has　shown　great　prospects　in　the　biomedical　fields　such　as　3D　printing　of　porous　scaffolds.　The　diameter　of　the　melt　electrospinning　writing　fiber　can　determine　the　resolution　of　the　microstructure;　thus,　the　controllability　of　the　fiber　diameter　is　of　great　significance　to　the　whole　fabrication　process.　In　this　paper,　an　orthogonal　design　experiment　(six　factors,　three　levels)　was　used　to　explore　the　impacts　of　six　melt　electrospinning　parameters　(melt　temperature,　collector　speed,　tip-to-collector　distance,　melt　flow　rate,　voltage,　and　needle　gauge)　on　the　fiber　diameter.　In　this　experiment,　the　diameter　of　fibers　obtained　with　the　designed　experimental　parameters　and　conditions　varied　from　10.30　&　mu;m　to　20.02　&　mu;m.　The　range　analysis　of　orthogonal　test　results　showed　that　the　melt　flow　rate　was　the　most　important　factor　influencing　the　diameter　of　melt　electrospinning　writing　fiber,　while　the　voltage　was　the　least　influential　factor.　The　variance　analysis　of　orthogonal　test　results　showed　that　melt　temperature,　collector　velocity,　tip-to-collector　distance　and　melt　flow　rate　had　a　significant　influence　on　the　diameter　of　melt　electrospinning　writing　fiber.　On　the　basis　of　the　first-order　regression　equation,　the　fiber　diameter　of　poly-&　epsilon;-caprolactone　can　be　accurately　controlled,　thus　improving　the　engineering　applications　of　poly-&　epsilon;-caprolactone.