Disclosed is an assembly type prefabricated light floor slab connecting device. The assembly type prefabricated light floor slab connecting device is composed of an H-type steel beam, an assembly type prefabricated light floor slab, studs and cast-in-place concrete. All the components are completed in factory; the assembly type prefabricated light floor slab is formed by connecting in a welding mode two floor slabs with reinforcing bars of a certain length; then the studs are welded onto the designated positions of the upper surface of the flange of the H-type steel beam; then the H-type steel beam and the assembly type prefabricated light floor slab are mounted in position at a construction site, and the concrete is poured onto connecting areas to complete assembly. According to the assembly type prefabricated light floor slab connecting device, all the components are prefabricated in history to achieve assemblage, so that the assembly type prefabricated light floor slab connecting device accords with the development trend of architectural industrialization and has the advantages of being reasonable in design, convenient to construction, simple in control of parameters of beams and slabs, capable of greatly shortening the construction period, achieving standardized and industrialized production, greatly promoting development of architectural industrialization and the like.