The invention discloses a RW-type horizontal well construction method and a drilling tool used by the RW-type horizontal well construction method. The key point of the technical scheme is that the drill tool comprises a drill bit and a plurality of sections of hollow drill rods, wherein the drill bit and the hollow drill rods are connected by a connecting assembly. The connecting assembly connectsthe drill bit with the hollow drill rods during drilling process, when the hollow drill rods are pulled out, the connecting assembly separates the drill bit from the hollow drill rods. The RW-type horizontal well construction steps are that a drilling machine is used for horizontal drilling, the drill rods are the multi-section spliced hollow drill rods, and the drill bit and the drill rods are detachably connected; during the drilling process or after drilling to a designed depth, and a filter tube is inserted into the hollow drill rods from a mouth of a drilling hole; the hollow drill rodsare pulled out, the hollow drill rods are separated from the drill bit, and the drill bit and the filter tube remain in the drilling hole. The RW-type horizontal well construction method is simple inoperation steps and good in working environment. The use of the drilling tool can improve the construction efficiency of horizontal wells.