Distributed cooperative control mode is an effective approach to overcome the problem of integrating multiple and strongly random distributed generators(DGs)into cyber-physical system in distribution network. However

due to the integration between cyber and physical layers

cyber attacks could threat the safe and stable operation of power system through invading the cyber system. Toward this end

a dynamic attack-defense game model based vulnerability assessment of cyber-physical system(CPS)in distribution network is proposed. Firstly

a cooperative control strategy of DGs is described

and its convergence property is analyzed and summarized. Then

a risk assessment of CPS in distribution network is developed

which integrates the risk assessment method

the cooperative control strategy of DGs and strategies of attacker and defender. After that

the dynamic attack-defense game function and its solving steps are designed

which achieves the vulnerability assessment of CPS in distribution network with distributed cooperative control mode. Finally

the effectiveness of the proposed method is verified through simulations involving the IEEE 34-bus distribution network.