To balance the reliability and economic of power distribution system, this paper proposes a multi-objective optimization model which is constructed with both reliability and economic targets. The adaptive multi-objective particle swarm optimization algorithm is used to solve the model, and to optimize the distribution system. This paper takes IEEE-RBTS Bus 6 as the illustrating example. Through system simulation, the Pareto optimal solutions are found which could help decision makers choose appropriate scheme according to their preference. In addition, the paper offers a new research way for the reliability and economic assessment in the renewable power system.