With the advent of HDTV, the high density DVD (HD DVD) and blue-ray disk (BD) series will become the mainstream. Compared with BD, HD DVD has lower producing cost and sailing price, and it can be compatible with DVD. We design a new kind of compact optical picking-up head (PUH) based on HD DVD technology. It is simple in structure and small in size. It has two laser waves, and can be compatible with DVD downward. The PUH is mainly composed of a penta prism, a collimating lens, and an objective lens. The light route is analyzed using ZEMAX, and the results turn out to be successful. The penta prism is used to achieve a much longer optical path, so that the PUH size is reduced.