The invention relates to a butterfly valve and a jetting device comprising the same. The butterfly valve comprises an actuator and a valve plate. The actuator comprises a piston cylinder and a first piston, wherein the first piston is assembled in the piston cylinder in a guiding and moving mode in the left-right direction. A rotary shaft connected with the valve plate is rotationally assembled on the piston cylinder, and the rotating axis of the rotary shaft is perpendicular to the left-right direction. A gear is fixedly and coaxially arranged on the rotary shaft. The right end of the first piston is provided with a first rack in engagement transmission with the gear so as to drive the valve plate to open when the first piston moves rightwards. The first piston is fixedly provided with a first piston rod, the axis of the first piston rod extends in the left-right direction, and the left end of the first piston rod penetrates out of the left side of the piston cylinder. A first limiting structure used for being matched with the piston cylinder in a limiting mode to limit the rightward moving limit of the first piston rod is arranged on the portion, located on the outer side of the piston cylinder, of the first piston rod. The invention provides the butterfly valve with the opening-angle-adjustable valve plate and the jetting device comprising the butterfly valve.