A damming machine for stacking sandbags at a dike breach for preventing flood, comprising two driving wheels (1), a driving axle housing (2), a sandbag bucket (3), an operating platform (4), and a cantilever (5); one end of the cantilever (5) is provided on a rotary table base controlled by a host of the operating platform (4), and the other end thereof is hingedly connected to a power arm (6); the power arm (6) comprises a telescopic arm (62) and a hydraulic cylinder (61) provided at one end of the telescopic arm (62); a piston rod of the hydraulic cylinder (61) is connected to the telescopic arm (62); the end of the power arm (6) is provided with a damming mechanism; the damming mechanism comprises a rotary table (63) provided at the other end of the telescopic arm (62) and a blocking base (64) provided on a rotary base of the rotary table (63); a support base (65) is provided on the blocking base (64), and is provided with a sandbag conveying mechanism; the sandbag conveying mechanism comprises a guide base (7) matching the support base (65) and a moving mechanism sliding along a guide slot of the guide base (7); a transmission mechanism is provided above the guide base (7). The damming machine can quickly and efficiently stack a plurality of sandbags continuously at a time without moving the position of a host of the damming machine. The damming machine is simple to operate, convenient to use and high in efficiency.