The invention discloses a roof steel structure for a cement production line clinker warehouse and a construction method thereof. The warehouse is a reinforced concrete circular silo of which the diameter is 40 meters, and comprises a roof steel structure, an H-shaped welded steel part annular beam, an equipment steel platform and a warehouse top house, wherein the roof steel structure consists of18 sloping beams, an inclined support, a horizontal support, a Z-shaped steel purlin and a brace; a circular steel plate is paved on the H-shaped welded steel part annular beam; the equipment steel platform consists of a bracket, a rectangular main beam and a planar steel plate; and the warehouse top house consists of steel upright posts and roof beams, wherein the lower port of each sloping beamis connected with a pre-embedded connecting piece on the top of a silo wall in a bolting and welding way; the upper port of each sloping beam is welded with the annular beam; and roof colored steel plates are paved on all roofs. The problems of large roof load and easiness in damaging are solved; and the problems of overhead central point positioning of the annular beam and overhead axial positioning of each sloping beam are solved. The roof steel structure for the cement production line clinker warehouse has a reasonable and practical structural design; and a method for hoisting members witha QTZ63 tower crane and a 50t crawler crane is adopted during construction, so that the roof steel structure is more suitable for building a cement production line clinker warehouse roof in remote places or places without sufficient building equipment.