Traditional island partition method does not use network topology properly, has bad searching performance, etc. Aiming at these problems above, this paper proposes an island partition method for distribution system based on Dijkstra algorithm. Firstly, the shortest path from DG node to important load node is found out by using Dijkstra algorithm. On meeting the constraint condition of islanded partition, the paths containing important loads are preferentially incorporated into island. Secondly, under satisfying safety and stability operation of island, more loads are incorporated into island gradually based on adjacent relation and load priority of the obtained islands. The proposed method can give full play to power supply capability of DG and has a good searching ability; it not only ensures power supply of the important load to maximum extent, but also considers the function of connective switch. Finally, the example analysis shows that the proposed method can solve the problem of distribution system island partition effectively.