The invention provides a hollow body. The hollow body is characterized in that a lower cover detachably covers the lower end of an annular lateral wall, an upper cover covers the upper end of the annular lateral wall, and an inner cavity is formed among the lower cover, the annular lateral wall and the upper cover. Preferably, the upper cover detachably covers the upper end of the annular lateral wall. The annular lateral wall is formed by folding a foldable part in a surrounding manner. A through hole is formed in the annular lateral wall. A plurality of vertical folding lines are vertically arranged on the annular lateral wall at intervals. The invention further provides a related hollow floor and a manufacturing and construction method of the hollow floor. The hollow body has the advantages that the hollow body is ingenious in design, simple in structure, convenient to store and transport, capable of increasing prefabricating rate, time saving, labor saving, capable of lowering cost and shortening construction period, safe, economical, environmental friendly, and suitable for large-scale popularization and application; the hollow body does not float in concrete which is not cured, the hollow body can be removed after being combined with a cured concrete base plate, water accumulation in the cavity is avoided, the related hollow floor can be prefabricated, and in-situ reinforcing steel bar laying and hollow floor pouring can be reduced.