The invention discloses a fixing mechanism with an adjustable angle for a water conservancy irrigation device. The mechanism comprises a bottom plate, a fixing frame and a limiting plate, a connectingrod is installed above the bottom plate, a fixing plate is arranged above the connecting rod, a side plate is fixed to the part above the fixing plate, a fastening bolt is installed on the left sideof the middle of the side plate, an adjusting screw is fixed to the right side of the fastening bolt, a fixing frame is arranged on the right side of the side plate, a rubber layer is arranged in thefixing frame, a fixing column is welded to the part below the fixing frame, lugs are installed on the two sides of the fixing column, screws are fixed to the upper portions of the lugs, and grounded nails are arranged below the screw lugs. According to the mechanism, a rotary structure is formed by the connecting rod through a rotary disc and the fixing plate, the connecting rod can be rotated through the rotary disc to make the adjustment of the irrigation direction, the rotary range between the connecting rod and the fixing plate is 0-180 degrees, the irrigation range is expanded, and the irrigation is more convenient.