Aiming at the issue of object localization in acoustic sensor networks, a method of hyperbola localization based on time difference of arrival is proposed. This method calculates the position of an object by employing a group of time differences which are formed by the acoustic signals arriving at various sensors. Three special sensors are employed to build the relative coordinates system and create their respective hyperbolas of acoustic source, the locations of an object can be calculated by these hyperbolas, which are expressed as the relative coordinates. These relative locations are transformed into the absolute locations by coordinates transforming. Simple simulations demonstrate this method has favorable localization accuracy.