The present invention relates to a high picture quality video streaming service method and system. The high picture quality video streaming service system according to the present invention includes: a content server for generating a first encoding video by encoding an original video with at a constant bit rate, generating a second encoding video by encoding the original video by using 1/N of the length of a first encoding video Group Of Pictures (GOP) and 1/N of a frame rate with constant Quantization Parameters, generating a streaming video by using the first encoding video and the second encoding video, and downloading the first encoding video and transmitting the streaming video in real time; and a user terminal for downloading and playing the first encoding video, or generating and playing a video for playback by recombining frames of the first encoding video and frames of the streaming video.