The invention provides a method and apparatus for determining the capability of receiving a distributed power supply by a distributed network feeder line. The method comprises the steps that: according to load information and line parameters of a receiving node of a distributed network feeder line, a feeder line loss value is determined; according to the feeder line loss value, a three-phase voltage changing quantity of the feeder circuit is determined; a maximum active value of distributed power access under the voltage constraint is determined by using a single phase having the largest voltage change among the voltage changing quantity; and a feeder current corresponding to the maximum active value is compared with a circuit current limit value and the capability of receiving the distributed power supply by the feeder line is determined. In addition, the apparatus consists of a feeder information acquisition unit, a voltage drop unit, a quantitative calculation unit and a result analysis unit. The method and apparatus provided by the invention can be applied to scheduling and operation control of a distributed power supply in a power grid; security access of the distributed power supply and secure operation of the power grid can be guaranteed; and the capability of receiving the distributed power supply by the distributed network is enhanced.