Abstract: The accident analysis model for integrated small reactor was established by the code of RELAP5/MOD3.2, including the reactor coolant system (RCS), simplified secondary system and safeguard system. The small & integrated modular multi-purpose passive low-emission economical reactor (SIMPLE) is a 660 MWt (>200 MWe) integral pressurized water reactor. A double-ended direct vessel injection (DEDVI) and a small break loss of coolant accident (SBLOCA) for the direct vessel injection line were analyzed. The results show that the break and automatic depressurization system can depressurize the RCS and the coolant from accumulator and in-containment refueling water storage tank can mitigate the accident consequence of DEDVI. The results also show that the safety system can effectively lower the temperature and reduce the pressure of RCS, also can prevent core overheating for SBLOCA.