The reliability analysis of large urban complex high-voltage distribution network is completed, which combines with the optimization goal of the interval resource optimization and network structure optimization for high voltage distribution network. Using PSASP and Matlab, it can access the PSASP database indirectly and improve the accessing speed of data interface. According to the depth first search, a complex distribution traversal search path table is constructed, which realizes the description of the architecture of complex distribution power grid and can be used in reliability analysis and grid architecture optimization flexibly. According to depth search path table and based on minimal cut-set method, the reliability analysis of complex high-voltage distribution network is achieved. Finally, the 29 node example and the actual complex high-voltage distribution network in Sichuan province are used to verify the correctness and effectiveness of the above program.