Abstract: Evaluation of feeder capacity is an important means to guaranteeing reliable operation of feeder. A method is proposed to calculate the available capacity of feeder partition satisfied with N-1 security criterion. Firstly, distribution networks at the same voltage level are divided into feeder partitions with automatic/manual switching devices as the boundary, which can be regarded as load nodes. The topology of the distribution network is described by all load nodes and all sets of power supply paths associated with load nodes. Taking path states as variables, the 0-1 linear programming model is developed to analyze N-1 security verification of feeders.To meet the practical marketing demand of the power supply company, by taking path states and the available capacity of feeder partition as variables, the mixed integer linear programming model is proposed to calculate the available capacity of feeder partition satisfied with N-1 security criterion. Finally, the calculation results of a practical 10 k V feeder group in a provincial capital show that the proposed method is practicable and effective.