Underground communication port pre-waterstop node structure and construction method

The invention relates to a pre-waterstop node structure of an underground communication port and a construction method, the pre-waterstop node structure comprises a plurality of prefabricated wallboards, and the prefabricated wallboards are vertically arranged at the communication port and located on a foundation; a first gap is formed between every two adjacent prefabricated wallboards, and a second gap is formed between the bottom of each prefabricated wallboard and the top end of the foundation; a first groove structure is formed in the position, corresponding to the first gap, of each prefabricated wall plate, every two adjacent first groove structures are opposite, and a water stop area is formed; a second groove structure is formed in the position, corresponding to the second gap, of each prefabricated wall plate; slab joint structures are formed on the two sides and the bottom of each water stop area through waterproof mortar; a bottom horizontal cavity is formed by the inner side of the lower horizont