According to the white paper “China's Aerospace 2021”，China's planetary exploration project will carry out asteroid exploration，Mars sampling return，and Jovian system exploration，but there is no clear plan for more long-term planetary exploration missions.The Saturn is the second largest planet in the solar system，with beautiful rings and many natural satellites，among which the Enceladus may have a subglacial ocean，and the Titan is the second largest natural satellite in the solar system and the only satellite with a dense atmosphere，all of which are of great scientific research value.In this paper，foreign Saturn exploration missions are investigated and analyzed，including Pioneer 11，Voyager 1，Voyager 2，and Cassini-Huygens，as well as the future missions，including Enceladus Orbilander and Enceladus Multiple Flybys.The characteristics of these missions and the key difficulties in the implementation of Saturnian system exploration are summarized.Finally，an overall mission assumption of Saturn system exploration is proposed，and the mission analysis and preliminary design are carried out，which can be used as a reference for China's follow-up planetary exploration mission planning.