This paper presents a multistage planning methodology for active distribution networks（ADN）planning which has not fully considered the defects of variable practical operation conditions, where the demand and distributed generation（DG） uncertainties are taken into account. Based on biogeography-based optimization, the forced affect and economy cost are analyzed by quantifying the uncertain factors under practical network operation, considering the network radial structure and expansion alternative, building the system composite cost function which can comprehensive reflect different constraints. Proposed weighted multidimensional optimization theory, designed expansion planning process and used lean management thinking to obtain the best system multi-stage expansion plan under distribution network planning according to the pseudo-dynamic programming method. After analyzing the results of example, the methodology can achieve the optimal design of planning and improve the system reliability and profit under practical operation effectively.