Abstract: A dynamic cascading failure model considering the probability characteristics of emergency control and protection device and DC system is proposed,with which dynamic simulation of the 2010 East China power grid is performed.Under conditions of different DC operation modes,DC control parameters,AC/DC interconnection modes,and AC/DC capacity distribution,the outage power-outage probability power law curves of the system are calculated,and the impact of the DC transmission on system self-organized criticality is analyzed.It can be seen from the results that in certain systems,the probability of cascading failure and blackout can be reduced by selecting a suitable DC transmission mode.