Abstract: This paper presents an efficient method to optimize the passive location accuracy base on communication and energy constrained wireless sensor network. Trade off the location accuracy and the computational complexity by set the scale of single cluster; based on the theory of the target position estimation variance is scaling the measurements error by GDOP (geometry dilution of position ), propose a two rounds passive location method : the first round, using RSSI location (Received Signal Strength Indicator) scheme by employ the whole sensor set to give the coarse estimation of target location.To estimate the TDOA location estimation variance by the product of GDOP (geometry dilution of position ) of cluster and the measurements error;The second round, select a part of clusters which have lower variance in the coarse estimation of target location, then using these selected sensors’ TDOA (Time Difference of Arrival) location solution weighted by location estimation variance to give the fine estimation of target location. Simulation results verify this method get rid of the redundant sensors efficiently, use half of sensors approach to the location accuracy of use all sensors.