Location precision of radiant source is the primary performance of passive location system, and how to improve location precision is an important problem which always attracts attention. In three satellites TDOA (Time Difference Of Arrival) passive location system, location precision of single pulse location is limited by the error of TDOA measure. For improving location precision of radiant source, multi-TDOA location algorithm which estimates the position of target combining all the TDOAs is proposed in this paper. The new algorithm calculates three satellites’ positions at the arrival time of each pulse firstly, and then combines all pulses’TDOA equations and earth equation, lastly estimates the position of radiant source using least square algorithm. The result of simulations shows that the new algorithm can improve location precision of radiant source, and it is a steady and effective location method with higher location precision.