Analyze the system reliability index for distribution networks with distributed generators (DG) based on the assessment methods of distribution networks. On the consideration to improve the reliability of system and user-side, analyze the impact of the application of distributed generators in distribution system to recloser and the other protective equipment, and choose a mathematical model with the optimal configuration of the position of distribution recloser. Combined with system economy, give the solving algorithm for this model by use of a genetic algorithm and verifies the effectiveness of this algorithm.