The invention relates to a light shell house and a construction method thereof. The light shell house comprises a building foundation fixed on the ground or water surface, a door frame which is taken as house columns and/or a window frame, a mudsill, a top beam, a skylight frame and EPS prefabricated panels. The construction method of the light shell house comprises the steps that: the building foundation on the ground or water surface is constructed; the door frame which is taken as house columns and/or the window frame on the building foundation are/is arranged, and the door frame and/or the window frame form/forms a light steel frame with bearing function by the mudsill, the top beam and the skylight frame; the light steel frame is adhered with the integral EPS prefabricated panels which fix the top wall so as to form the integral light shell house. The light shell house and the construction method of the invention have the advantages of energy saving, land saving, ecological environment protection, earthquake resistance, weather resistance, low cost, short construction period, fast speed, free separation and combination of indoor space, being suitable for multi-function application and industrial integration.