The invention belongs to the field of building construction and provides a novel prefabricated house and a construction method thereof. The novel prefabricated house comprises a plurality of house units, each house unit comprises an overlapped dense-rib mould box floor plate and a plurality of latticed frame shear wall bodies, and the overlapped dense-rib mould box floor plate of each house unit is mounted at tops of the latticed frame shear wall bodies. Each overlapped dense-rib mould box floor plate comprises an upper plate, a lower plate and in-plate rib beams, wherein the upper plate and the lower plate are in opposite arrangement, the in-plate rib beams are positioned between the upper plate and the lower plate and fixedly connected with the upper plate and the lower plate, and the lower plate is fixedly connected with the latticed frame shear wall bodies. The construction method is used for construction of the novel prefabricated house. By standard design and industrial production of multiple parts of the house, standardization, unification and diversification of key parts are realized while quality of prefabricated components is improved, and diversified requirements of different types of houses can be met.