In complex imaging settings, optical scattering often prohibits the formation of a clear target image, and instead, only a speckle without the original spatial structure information is obtained. Scattering seriously interferes with the locating of targets; especially, when the scattering medium is dynamic, the dynamic nature leads to rapid decorrelation of optical information in time, and the challenge increases. Here, a locating method is proposed to detect the target hidden behind a dynamic scattering medium, which uses the a priori information of a known reference object in the neighborhood of the target. The research further designs an automatic calibration method to simplify the locating process, and analyzes the factors affecting positioning accuracy. The proposed method enables us to predict the position of a target from the autocorrelation of the captured speckle pattern; the angle and distance deviations of the target are all within 2.5%. This approach can locate a target using only a single-shot speckle pattern, and it is beneficial for target localization in dynamic scattering conditions.