Abstract: As the increase of distributed generation penetration level and load volatility, the uncertainties in distribution networks are coming complex and severe. While bring challenges to the planning and operation of distribution network, which also indirectly requests higher accuracy of uncertainty power flow calculation. Concerning the impact of distributed generation and load uncertainty on power flow analysis in distribution network, a new fuzzy power flow calculation method is proposed. Firstly, the nested characteristics of distributed generation and load sampling data are analysed, and power fuzzy model based on membership matching function is constructed to make up the insufficient basis and subjective in fuzzy modelling of conventional method. Then, the parameterized membership matching function is combined with forward-backward sweep method. By using parametric iterative operation, the fuzzy power flow of the distribution network is solved, which avoids the low operation speed or low calculation precision of a-cuts decomposition and approximation processing. Finally, a practical distribution network is used in case study, the results can not only reasonably characterize the uncertainty of distributed generation and load, but also quantitatively analyse the possible changes of voltage profile and power distribution values, which verified the validity of the proposed fuzzy power flow calculation method.