The present invention relates to a cavity mould casing component, comprising an upper plate (1), a surrounding side wall (2), a lower base plate (3) and a toss (4), wherein, the upper plate (1), the surrounding side wall (2) and the lower base plate (3) are enclosed to form an enclosed cavity, and the toss (4) is stretched out from at least one outer side of the lower base plate (3). The present invention is characterized in that at least the toss (4) on one side adopts a composite layer toss folded by tossing, and the composite layer toss comprises at least one prefabricated layer (5), the prefabricated layer (5) of the composite layer toss (4) is superposed with a cast and coat-in-site layer (6), namely superposed with one cast and coat-in-site layer (6), one prefabricated layer (5) then another cast and coat-in-site layer (6), the prefabricated layer (5) in the composite layer toss (4) is a prefabricated edge linked with the surrounding side wall (2) or a prefabricated plate or a pre-embedded sheet or a prefabricated sheet with a connection piece. The present invention is suitable for the hollow floor, the roof, the wall body, the base plate and the spatial bridge of the cast-in-place concrete or the prestressing reinforced concrete, and is especially suitable for the hollow non beam hollow floor.