The utility model provides a large multifunctional over-water construction platform, consisting of an upper layer part and a lower layer part, wherein the upper layer part is formed by connecting a row of upper transverse beams and a row of upper longitudinal beams in a perpendicular crossing way; the lower layer part is formed by connecting a row of lower transverse beams and a row of lower longitudinal beams in the perpendicular crossing way; the upper transverse beams and the lower transverse beams are uprightly corresponding in a one-to-one way, and are respectively and integrally connected by upright rods and diagonal braces; the upper longitudinal beams and the lower longitudinal beams are also uprightly corresponding in the one-to-one way, and are respectively and integrally connected by upright rods and diagonal braces; the every two adjacent upper transverse beams and the every two adjacent upper longitudinal beams surround a vertical space in the shape of a regular quadrangular prism; the every two adjacent lower transverse beams and the every two adjacent lower longitudinal beams also surround a vertical space in the shape of a regular quadrangular prism; the vertical spaces are respectively and internally provided with a guide device. According to the large multifunctional over-water construction platform, as the construction technology of a multifunctional platform for the splicing of floating bodies and the floating transportation is utilized, little large over-water equipment is needed; the shoreside processing and installation are convenient without the preliminary construction of a trestle; therefore the work period is shortened, and the construction cost is reduced.