This paper designs a novel 3D SRAM soft error analysis platform. It is used for studying the soft error characteristic of 3D SRAM stacked by multi dies and guiding the radiation hardened design for 3D SRAM. This platform integrates simulation tools including Geant4, TCAD and Nanosim, data recording and processing tools ROOT, layout processing tools Calibre, and Perl and Shell script used for linking task and analyzing results. After inputting the stacked structure, technology, circuit netlist and layout of 3D SRAM and incident particles information, this platform can simulate the particle striking 3D SRAM automatically, and then we get some kinds of cross sections, error information in a single word and sensitive node distribution for 3D SRAM. A 2 die stacked 3D SRAM based on 65nm CMOS technology is analyzed through this platform.