To improve the power distribution reliability and economy of distribution network，the multi-scenario and multi-objective survivability optimization model based on the shortest possible path is created from the perspective of optimizing its network structure and connectivity.For the scenarios of normal operation and all single post-failure scenarios，with minimum transmission loss and none or least load-shedding respectively as the objective，the topology with the best survivability of distribution network that has ever been built is found using the branch-exchange algorithm for optimization.A new research approach is put forward for the topological optimization of the medium voltage distribution network.The optimal results based on the approximate IEEE33-bus distribution network test system indicate the rationality and practicality of the proposed method.