FDSOI technology has attracted considerable interests in space application due to its inherent high radiation resistance. An SEU hardened 8T SRAM cell is proposed and implemented in a test memory chip with advanced 22 nm UTBB FDSOI technology. Heavy ion experimental results show that the threshold LET of SEU for proposed 8T structure cell is up to ~24 MeV·cm2·mg−1 and less dependences of upset on data pattern and test modes are observed. Moreover, multiple bit upsets are not appeared in bitmap analysis results even under effective LET values at ~129 MeV·cm2·mg−1. The Pbb body biasing shows low influence on SEU rates in irradiation test, while the Nbb body biasing has ability to adjust the SEU sensitivity in a certain range. The error rate prediction indicates that this nanoscale FDSOI hardened SRAM is suitable for space application in harsh radiation environment.