A cast-in-situ concrete filling component comprises a sealing cover plate, a 
peripheral side face, a lower bottom plate and 
filling materials, and is characterized in that the 
filling materials are arranged in a cavity with an opening, the cavity is defined by the lower bottom plate and the 
peripheral side face, the opening of the cavity defined by the lower bottom plate and the 
peripheral side face is connected with the sealing cover plate, and the sealing cover plate, the peripheral side face, the lower bottom plate and the 
filling materials are sealed and overlapped to form a whole 
solid; a shell defined by the sealing cover plate, the peripheral side face and the lower bottom plate contains at least one of or more than one of or all of 
cement concrete, early strength agents, accelerating agents, 
sodium silicate, 
cellulose ether, polycarboxylate-type high-performance water reducing agents and 
polymer anti-crack 
mortar; the filling materials are formed by AB foam forming 
stearin and polyphenyl boards in a coextrusion mode. In addition, a protruding fixed component can be arranged on the face of the lower bottom plate according to the technological base or a formwork stretching outwards is arranged on the side face of the periphery of the lower bottom plate or chamfers are arranged along the periphery of the lower bottom plate and the periphery of the sealing cover plate. The cast-in-situ concrete filling component has the advantages of being easy and convenient to install, high in production efficiency, low in construction cost, high in seismic 
crack resistance and crush resistance, high in surface 
hardness and the like.