Abstract: With vast distributed resources accessing the distribution system, the multiple sources can be coordinated for load restoration, enhancing the restoration rate and the supply duration of the loads, and improving the space penetration and the utilization rate of distributed sources. This paper proposes a multi-source cooperative restoration method considering islanding integration to improve the distribution system restoration effects. A restoration model with the objectives of minimizing the load loss, the network loss and the power output variation is developed. Except for the conventional restoration constraints, the constraints on islanding integration and load adjustment are proposed for expanding the scope of integrated islands. A source-load islanding integration index is put forward to select the reasonable strategy of islanding integration. The proposed model is transformed into a mixed-integer second-order cone programming model by relaxing the nonlinear constraints of the power flow in order to be solved. Case studies on the improved IEEE33-bus and the PG & E69-bus distribution test systems verify the effectiveness of the proposed method. Compared with the existing methods, this proposed method has a superiority in the coordination of power sources, the space penetration of distributed sources, the restoration rate and the supply time of loads. It can also deal with the risks of source failures.