The invention relates to the technical field of sewage treatment, in particular to a precipitation device for sewage treatment. The precipitation device for sewage treatment comprises a sewage treatment device, a first sewage pipe, a first valve and a second sewage pipe, wherein the first sewage pipe and the second sewage pipe distributed up and down are fixedly connected to the right end surfaceof the sewage treatment device; the first valve is fixedly connected to the upper end surface of the first sewage pipe; a second valve is fixedly connected to the upper end surface of the second sewage pipe; the other end of the first sewage pipe is fixedly connected with the second sewage pipe; a precipitation tank is fixedly connected to the other end of the second sewage pipe; a buffer device is fixedly connected to the inner wall of the left end surface of the precipitation tank; a sterilization device is fixedly connected to the upper end surface of the right side of the precipitation tank. According to the precipitation device for sewage treatment provided by the invention, through arranging a sewage tank, a motor, a telescopic rod, a hairbrush plate and a hairbrush block, the devicecan be enabled to be recycled, is simple to operate, convenient to use, and high in automation degree, and has good use benefit.