Supporting device for plain river channel dredging project and construction method thereof

The invention discloses a supporting device for a plain river channel dredging project and a construction method thereof. The supporting device comprises a fixing seat, a supporting frame and a supporting mechanism, wherein a fixing rod is limited by a positioning strip and provided with a fixing block; the fixing block is provided with a fixing groove; the fixing seat is provided with connecting blocks; fixing bolts are arranged in the connecting blocks on the two sides of the fixing block in a penetrating mode and arranged in the fixing groove; the fixing block is limited by the fixing bolts; the supporting frame is provided with supporting rods and clamping sleeves; the supporting rods are provided with clamping rods; the clamping rods are arranged in the clamping sleeves; the supporting rods are provided with guide blocks and sliding grooves; and a water retaining mechanism is arranged between every two adjacent supporting rods. The method comprises six steps. According to the supporting device for the pl