The invention discloses a distributed power supply access-based feeder liner optimization planning method. The method comprises the following steps of drawing a typical daily load characteristic curve and selecting the maximum load moment; obtaining the minimum output value under n% output probability, predicting the maximum load in the planning region, performing electric power electric quantity balance, and planning the number of substations and power transformation capacity; calculating the feeder line maximum access distributed power supply capacity under capacity limitation; performing power flow calculation and short circuit calculation on the feeder line, and verifying the voltage and short circuit current of each node; and formulating a power distribution network safety evaluation model, calculating unsafe loads under 1-n% probability distributed power supply output and performing judgment. The method has the beneficial effects as follows: by taking non-out-of-limit property of the node voltage and short circuit current in power flow calculation as the constraints, the reasonability of the planning scheme is verified by taking the maximum access capability of the feeder line and the substations and the power grid safety as conditions, so that the problem that the conventional planning method cannot realize global optimization and planning in orientation of a large number of distributed power supply access can be solved.