Construction method of prefabricated multi-ribbed cavity floor

The invention provides a construction method of a prefabricated multi-ribbed cavity floor, and belongs to the technical field of prefabricated multi-ribbed plate construction. The construction method of the prefabricated multi-ribbed cavity floor comprises the steps of full-hall scaffold building, main keel laying, overall leveling and the like. The construction method comprises the steps that S1, full-hall scaffold building is conducted, specifically, when a full-hall scaffold is built, vertical rods on the upper layer and the lower layer are required to be aligned, the vertical rods are uniformly arranged from the two sides of a cast-in-place ribbed beam, the vertical rods are arranged at the intersection positions of floor elastic bidirectional lines, and scaffold boards are laid under the vertical rods; S2, main keels are laid, specifically, when the main keels are installed, the main keels are required to be arranged in order and not to be inclined, and the two vertical rods at the intersection positions must abut against the main keels; and S3, overall leveling is conducted, specifically, after the main keels are laid, overall leveling is conducted according to control lines, and full-hall scaffold formworks are hoisted on the main keels. The cavity formworks are supported by placing the modularized cavity formworks which are machined and formed in a factory-like mode, and accurate and rapid installation of an upper plate of the prefabricated multi-ribbed plate is achieved by installing limiting square pipes.