Power network topology analysis is a basic task of power grid dispatching automation system and a bridge of connecting power grid model and analysis, providing the necessary basic data for power flow calculation and anti misoperation, etc. With the development of power grid construction and gradual expansion of the network structure, a new method, in full use of computer resources to achieve high efficient network topology analysis is needed. This paper presents a topology analysis algorithm based on divide-and-conquer algorithm, which can be realized by combining with the characteristics of grid model and mature graph algorithm. At the same time, topology functions of the high-level application service oriented and monitoring service oriented are decoupled, which can improve dispatching automation systems integration efficiency without affecting power flow calculation, finally the concurrent program for distributed power network topology analysis when applying the proposed algorithm is written and its application prospect is proposed.