Abstract: Oil shale in-situ retorting technologies are the trend of large scale commercialized development of oil shale in the future. Among them, the fluid heating technology has attracted more and more attention due to its distinct advantages as fast heating, adequate usage of retorting gas, and relatively mature technology, etc. In view of the problems existing in fluid heating technology for oil shale in-situ retorting both at home and abroad, this paper presents a new idea of fluid heating, that is, using the combined technology of staged fracturing of horizontal section and superheated steam assisted gravity drive to produce the oil shale resources with great burial depth (300~1000 m); its main principle is to inject overheated steam through the complex fracture network created during staged fracturing of horizontal section to heat the oil shale reservoir and gradually convert the kerogen to liquid hydrocarbons, the liquid hydrocarbons so produced then flow to the producing well through the fractures, and finally flow to surface in conventional method. Taking the oil shale basin in Huangxian Basin in Longkou, Shandong, this paper presents a design scheme for fluid heating technology, which has significant reference value for pilot tests from now on.