The invention discloses a prefabricated bottom plate with cold-formed thin-walled steel ribs, a laminated plate and a manufacturing method of the prefabricated bottom plate. The prefabricated bottom plate with the cold-formed thin-walled steel ribs comprises the longitudinal cold-formed thin-walled steel ribs, prefabricated bottom plate prestressed steel bars, prefabricated bottom plate structural steel bars and cold-formed thin-walled steel rib structural steel bars. The two longitudinal cold-formed thin-walled steel ribs with the same shape penetrate through holes reserved in the lower parts of the ribs through the prefabricated bottom plate structural steel bars and are connected with the upper parts of the two ribs through the cold-formed thin-walled steel rib structural steel bars, and a steel bar-cold-formed thin-walled steel framework is prefabricated. The prefabricated bottom plate prestressed steel bars and the prefabricated bottom plate structural steel bars are pre-buried in concrete to form the prefabricated bottom plate. The prefabricated bottom plate with the cold-formed thin-walled steel ribs is good in integrality and anti-seismic property, good in fire resistance and durability and simple and convenient to construct, on-site supporting is not needed, the construction period is short, the difficulty is low, the manufacturing cost is low, hoisting and transporting are easy, and the prefabricated bottom plate is suitable for multistory and high-rise buildings and large-span floor structures.