Abstract: The safety characteristics and radioactive release mechanism of pool type sodium-cooled fast reactor (SFR) are significantly different from those of pressurized water reactor. Under the new nuclear safety requirements, the research on probabilistic safety assessment (PSA) of radioactive release risk for SFR is urgently needed. Taking the pool type SFR as the research object, the main position and mode of large radioactive release were identified and the radioactive release event trees were constructed by analyzing the radioactive source, the containment boundary and the severe accident that might challenge the integrity of the containment boundary. The results can serve as reference for further research on PSA of radioactive release risk for pool type SFR.