The invention provides a slurry-bed loop reactor, comprising an ascending pipe and at least one downtake pipe 3, wherein, the ascending pipe consists of a reaction zone 1 and a settlement zone 2 with an expanded pipe diameter; an exhaust port 13 is arranged on the top of the settlement zone 2; the inside of each downtake pipe 3 is divided into a filtrate zone 5 and a slurry zone 6 by a filter medium 4, wherein, the filtrate zone 5 is communicated with a liquid discharge port 10; two ends of the slurry zone 6 are communicated with two ends of the ascending pipe 1, so the settlement zone 2 is separated into a steady flow zone 19 and a turbulent flow zone 20, wherein, the upper part of the steady flow zone 19 is communicated with the downtake pipe 3 through a pipeline 16; and the bottom of the steady zone 19 is directly communicated with the reaction zone 1 through an open pore 18 or through a draft tube 17. The slurry-bed loop reactor provided by the invention can realize continuous high-efficiency separation of solid catalyst particles, a liquid product and reacting gas, realize continuous discharging of a gas phase, a liquid phase and a solid phase, reduce turbulence of rising slurry from the reaction zone to settling particles in the settlement zone by separating the settlement zone into the turbulent flow zone and the steady flow zone, improve the separation efficiency of the settlement zone, and reduce the filtering load of the downtake pipe, thereby improving the treating capacity and the separation efficiency of the whole reactor, and prolonging the backsurge period.