A prefabricated partition wall structure of a lateral smoke exhaust passageway of a shield tunnel mainly comprises a lateral smoke exhaust passageway partition wall body, multiple vertical steel keels and multiple horizontal steel keels, wherein the multiple vertical steel keels and the multiple horizontal steel keels are mounted in the lateral smoke exhaust passageway partition wall body and used as main bearing members of the lateral smoke exhaust passageway partition wall, a plurality of concrete prefabricated wallboards are used as partition wall body wallboards and sequentially arranged and fixed on the vertical steel keels and the horizontal steel keels, the top portion of each concrete prefabricated wallboard is fixedly connected with a shield duct piece, and the bottom portion of each concrete prefabricated wallboard is fixed on a partition wall base. According to the prefabricated partition wall structure of the lateral smoke exhaust passageway of the shield tunnel, prefabricated structures are adopted, standardized and modular production is realized, the construction speed is high, a large quantity of manpower resources and a large quantity of material resources of site construction can be saved, and good social benefits are obtained.