In order to achieve fast and accurate assessment of power supply reliability in distribution networks

the similarity of network topology was introduced

thereby

an approach was proposed on reliability assessment of distribution network. In this method

the singular value sequence

as a goal of solving similarity indexes

was used to construct a quantitative mathematical relationship between similarity of network topology and power supply reliability of distribution network. First

the matrix representation and similarity indexes and its determination methods of network topology were introduced

and then the compression and reconstruction of matrix were analyzed so as to ensure topological property of adjacent matrix. Secondly

based on topology similarity

a novel algorithm was presented for power supply reliability assessment

in which the topology database and root mean square（RMS） method were used to decide similarity and modify reliability indexes.Finally

a calculation flow chart was given

and the topology of IEEE 33-node distribution network was taken as a case study

which shows that the calculation efficiency of the proposed method is seven times that of congeneric algorithms while the calculation accuracy is the same. The research can provide a reference and guide for the research of improving the power supply reliability assessment of distribution network.