Abstract: Pool type sodium cooled fast reactor is the preferred reactor type for the fourth generation reactor. The double-layer container leakage in the primary container will cause sodium leakage and severe accident. The probabilistic safety analysis method was used to analyze the double-layer container leakage of sodium cooled fast reactor, which could not only complete the severe accident analysis of the pool type sodium cooled fast reactor, but also provide reference for the design of the pool type sodium cooled fast reactor. The classifications of the process and accident consequences of the pool type sodium cooled fast reactor double-layer container leakage after the accident were described in detail. The frequency of radioactive release caused by leakage of double-layer container is 1.07×10^-11 (reactor•year)^-1, and large release frequency in double-layer container is 0.1%.