The problems exiting in reliability calculation of distribution automation, which fault diagnosis and switch control is not comprehensive enough. A reliability rate algorithm which is based on terminal configuration impact relationship is put forward. The feeder is aplit into base segment, then determining feeder segmentation relationship matrix and feeder base segment influence matrix based on terminal location. Then the solution value is obtained. This paper proposes three terminal configurations of overhead lines are simulated and calculated.Simulation result shows that this method can solving the reliability rate with different types and locations. Then it will provide reference for the selection of distribution automation terminal configuration schemes.