The invention relates to the field of sewage treatment and discloses a solid-liquid separator, comprising a sewage delivery screw pipe, a sewage intercepting mesh, two precipitating tanks communicated at least in the upper portions; the bottoms of the precipitating tanks are of conical structure, the bottom conical tip portions of the precipitating tanks are connected to the sewage delivery screw pipe, the upper portion communicated part of the precipitating tanks is transversely provided with a semicircular groove, the sewage intercepting mesh is of disc structure with the lower portion extended into the semicircular groove, the sewage intercepting mesh is provided with a center shaft and is connected to a drive mechanism that drives the sewage intercepting mesh to rotate around a center shaft, the most downstream precipitating tank is provided with a water outlet, and the water outlet is also provided with the sewage intercepting mesh. With the sewage delivery screw pipe at the bottom, the solid-liquid separator delivers out precipitated dirt quickly, such that the impact on sewage treatment is decreased; the sewage intercepting mesh may be driven by a drive mechanism to rotate, such that dirt can be effectively decreased which blocks the sewage intercepting mesh, and treating efficiency is improved accordingly.