The invention provides a method for retrieving an Internet video based on contents. The method comprises the following steps of: 1, acquiring a plurality of videos serving as a training sample set from Internet, building a video library, and extracting a blocking color histogram characteristic and a brightness characteristic of each frame in all videos in the training sample set, wherein the blocking color histogram characteristic and the brightness characteristic are used as a segmentation judging basis of a camera; 2, self-adaptively segmenting the camera for all the videos in the training sample set according to the two kinds of characteristics extracted in the step 1, and acquiring a camera segmentation list; 3, extracting key frames for all videos in the training sample set accordingto the camera segmentation list and the characteristics and acquiring the indexes of the key frames; and 4, for a video to be retrieved, performing the steps 1, 2, and 3 to acquire the key frame list, and fast positioning and retrieving by using a new soft judgment method. By the method for retrieving the Internet video based on contents, videos can be fast positioned and retrieved; and the method is high in the processing speed, the retrieval efficiency and the retrieval accuracy rate.