Novel　metal　halide　perovskite　is　proven　to　be　a　promising　optoelectronic　material.　However,　fabricating　microscopic　perovskite　devices　is　still　challenging　because　the　perovskite　is　soluble　with　the　photoresist,　which　conflicts　with　conventional　microfabrication　technology.　The　size　of　presently　reported　perovskite　devices　is　about　50　mu　m.　Limited　by　the　large　size　of　perovskite　optoelectronic　devices,　they　cannot　be　readily　adopted　in　the　fields　of　imaging,　display,　etc.　Herein　a　universal　microscopic　patterned　doping　method　is　proposed,　which　can　realize　microscale　perovskite　devices.　Rather　than　by　the　conventional　doping　method,　in　this　study　the　local　Fermi　level　of　perovskite　is　modulated　by　the　redistributing　intrinsic　ion　defects　via　a　polling　voltage.　A　satisfactorily　stable　polarized　ion　distribution　can　be　achieved　by　optimization　of　the　perovskite　material　and　polling　voltage,　resulting　in　ultrafast　(40　mu　s),　self-powered　microscale　(2　mu　m)　photodiodes.　This　work　sheds　light　on　a　route　to　fabricate　integrated　perovskite　optoelectronic　chips.