The invention discloses a bathroom water blocking groove construction technology. The construction technology comprises the following steps that S1, a pipe opening is blocked; S2, a base layer is cleaned; S3, the periphery of a pipeline is cleaned; S4, line snapping is carried out; S5, arc plastering is conducted, and specifically, arc plastering treatment is conducted on cement mortar through a special arc plastering tool at the pipe opening of the pipeline and the internal corner of the ground; S6, a water blocking groove is manufactured, and specifically, the water blocking groove is formed in a doorway of a kitchen or a bathroom, wherein the height of the water blocking groove is 1.5 cm, and the width of the water blocking groove is 10 cm larger than a door opening; and S7, waterproof construction is conducted, wherein waterproof paint is painted on the ground and the wall face according to the known technology, the waterproof paint needs to be painted on the water blocking groove, and a water closing test is conducted. The construction technology has the beneficial effects that the water blocking groove which is wider 10 cm than the door opening and is 1.5 cm high are formed in the doorway of the kitchen or the bathroom, water vapor can be isolated in the water blocking grooves, the situation that the water vapor enters other structures through a tile paving layer, and then a door pocket and a wall face are affected with damp is avoided, and the service life of indoor decoration is prolonged.