Infrared　photodetectors　were　widely　applied　in　satellite　detection,　infrared-guided,　infrared　early　warning　and　infrared　imaging　and　so　on.　Currently,　InAs/GaSb　type-II　superlattices　(T2SLs)　photodetectors　have　been　attracted　by　their　unique　band-structure　and　potential　applications.　In　this　paper,　the　InAs/GaSb　T2SLs　photodetectors　in　mid-wavelength　infrared　(MWIR)　spectral　range　were　fabricated　with　p-i-n　structure,　and　the　process　parameters　were　optimized.　The　multilayer　structure　was　grown　on　GaSb　substrate　by　Molecular　Beam　Epitaxy　(MBE).　The　active　area　of　this　photodetector　was　260　mu　mx260　mu　m,　and　the　sidewall　of　mesa　was　protected　by　SiO2　layer.　The　thickness　of　adsorption　layer　was　1060　nm.　To　reserve　more　incident　area　and　to　avoid　the　damage　caused　by　welding　process,　the　pad　of　electrodes　were　designed　under　the　mesa.　A　annular　electrode　was　designed　to　shorten　the　transmission　time　of　carriers　to　improve　the　collection　efficiently.　The　cut-off　wavelength　lambda(c)　of　the　detector　was　4.2　mu　m@77K,　and　the　dark　current　density　was　measured　as　1.07x10(-3)　A/cm(2)@V-b=-0.1V.　The　peak　of　specific　blackbody　detectivity　(D*)　was　equal　to　1.05x10(10)　cmHz(1/2)/W　at　zero-bias.