The invention discloses a combined type folding dam and a construction method thereof. The combined type folding dam comprises a folding dam body, a dam base plate, an edge pier, a middle pier, a pump room, an overhaul channel and the like, and is characterized in that the folding dam body is fixedly hinged to the dam base plate; two ends of the folding dam body are movably pressed against the edge pier A and the middle pier; when water is filled into the folding dam body, the folding dam body can be automatically lifted to stop and accumulate water from the upstream of a riverway; when the water in the folding dam body is drained, the folding dam body can be inclined towards the downstream, and the dam height is automatically reduced; and water flow overflows from the top of the folding dam body and flows into a riverbed after being subjected to energy consumption through an apron. The dam is suitable for a stratum of a wide and shallow river valley, so that requirements on adjustment of library capacity, overflowing from the top of the dam and large discharging flow can be met; and the combined type folding dam has the characteristics of good water flow state, automatic control over dam height, simple structure, convenience in operation, simplicity in construction and maintenance and the like and is a hydraulic structure capable of stopping and releasing the water.