The invention belongs to sewage treatment devices, and relates to a domestic sewage treatment device. The domestic sewage treatment device is mainly characterized in that a horizontal tank body is internally and separately provided with a sedimentation aging cavity, a scum separation net, a grit filtering cavity, an active adsorption cavity and a bio-enzyme catalysis cavity, wherein the sedimentation aging cavity is provided with dredging pipes. According to the domestic sewage treatment device disclosed by the invention, septic tanks of the existing living area are greatly modified, and domestic sewage is comprehensively treated by multiple multi-cavity continuous manners; and the domestic sewage treatment device disclosed by the invention has the remarkable advantages that the treatment cost is low, the purification effect is good, the living environment is improved, the treated domestic sewage reaches the national comprehensive drainage standard, a problem that the domestic sewage pollutes underground water and rivers is effectively solved, the blockage of underground pipes is avoided, the loads of sewage treatment plants are reduced, dredging and cavity cleaning operations are convenient, the service life is prolonged and the like.