To localize the pulse emitter, this artucle presents a new multiple-observer passive localization method by means of the time difference of arrival (TDOA) sequence in a short observation period. Firstly, the mathematical model of the TDOA sequence is established, and then the Cramér-Rao lower bound (CRLB) of the localization method is deduced. Moreover, the article proposes a computationally efficient solution named the two-stage localization method(TSLM). In the first stage, the TDOA and its rate of change are linearly estimated using the TDOA sequence. In the second stage, the emitter position is obtained by the TDOA and its rate of change. Finally, the article analyses the localization performance in typical scenes. The result shows that the TSLM estimate is with small bias in a short observation period, but the location error approximately approaches the CRLB. Besides, the smaller the pulse repetition period (PRI) is, the better the localization performance of the short time TDOA sequence is. The more quickly the observers move, the better the localization performance is.