For a distribution system with distributed generators（DGs），the islanding scheme and stochastic DGs output make higher request to the network planning.The service restoration ratio is first defined considering the stochastic DGs output and power load，and a multi-object flexible network planning model is presented for a distribution system with DGs.The model takes economy investment and supply reliability as optimization objectives，and service restoration ratio，subarea supply，network connection mode and flexible constrained branch power flow and node voltage as constraint conditions.In the reliability revolution of the proposed planning mode，the effects of stochastic DGs output and power load to service restoration are included，thus the limitations of existing planning model can be broken through.The obtained network planning schemes can adapt widely to DGs access and make full utilization of its islanding scheme ability.Calculation and analysis based on an actual example are performed.The results indicate the validity of the method proposed，by which the theory basis of network planning for a distribution system with DGs can be provided.