Detecting a specific person in video sequence is a challenging problem. We propose a real-time video detection method based on robust Hash signature. The approach consists of three steps. First, it devises the robust Hash function and computes the signature of the target image. Then, the signature of every representative key frame is acquired from the video sequence. Finally, the distance of two signatures is calculated to decide whether the target image is present. The proposed approach can capture key frames that may include a specific person in real-time, and locate the shot containing the detected key frames. Experimental results demonstrate that the approach can achieve high accuracy for retrieving repetitive specific information from video sequences, and can be used in applications such as detecting image copies and duplicate contents.