The invention discloses a construction technology for a sunken-type bathroom and relates to the technical field of bathroom construction. The construction technology comprises the following steps thatS1, a foundation drainage part is arranged, specifically, a foundation drainage channel is formed in a structural layer; S2, a foundation waterproof part is arranged, specifically, a structural waterproof layer is made on the structural layer; S3-1, supporting columns are built, specifically, the multiple supporting columns are evenly arranged at intervals; S3-2, drainage pipes are arranged in aburied mode, specifically, the top drainage pipes are arranged in spaces formed by the supporting columns in the buried mode; S3-2.1, water storage testing is conducted; S3-3, water absorbing and permeating layers are laid, and chambers formed by the supporting columns are filled with mixtures of light ceramsite and high-water-absorption fibers; S3-4, a bearing layer is poured, reinforcement fabrics are placed on the supporting columns, and concrete is laid on the reinforcement fabrics; S4, the bearing layer is subjected to waterproof treatment; and S5, ceramic tiles are laid, and joint filling is conducted on the connecting positions of the adjacent ceramic tiles to form pointing joints. According to the construction technology, by arranging an empty space integrates the water absorptionand drainage functions, the effect of reduction of water seepage of the bathroom is achieved.