The invention relates to a prestressed concrete cast-in-place hollow slab filled with light material combined units, belonging to the field of general building structures. It consists of light material combination unit, upper reinforcement, lower reinforcement, prestressed reinforcement, concealed beam reinforcement and concrete, wherein the light material combination unit consists of light pipe and connecting reinforcement. This kind of cast-in-place slab takes into account the advantages of prestressed structure and hollow slab structure, and has high hollow rate, which is suitable for both one-way slab and two-way slab. It is very convenient to lay pipes and tendons, and can also realize one-time pouring and molding of concrete. This cast-in-place slab has the advantages of large span, light weight, good sound and heat insulation effect, good structural reliability, earthquake resistance and crack resistance. The invention is invented by Changsha Giant Star Lightweight Building Materials Co., Ltd., and has good economy and applicability.