The utility model relates to a device of a dam icing-resisting system, namely a floating cylinder position control device. The floating cylinder position control device comprises two horizontally-arranged tripods which are at intervals up and down. A vertical hollow circular cylinder which is integrally connected with the two tripods is arranged between the two tripods, and a fixing connecting body is formed. A limiting rod is inserted into the hollow circular cylinder in a hanging mode. A limiting ring which slides up and down along the limiting rod is arranged at the lower end of the limiting rod in a sleeving mode. An icing-resisting device water draining main pipe is connected to the limiting ring horizontally. A blocking body with the diameter larger than that of the hollow circular cylinder is arranged at the upper end of the limiting rod. According to the floating cylinder position control device, mounting, detaching and maintaining of an icing-resisting device are easy and convenient. The vertical and horizontal positions of the icing-resisting device can be controlled effectively. The whole position control device is simple in structure and convenient to manufacture, and large-scale using can be well achieved. Economy and durability are achieved, using for a long time can be achieved, and repeated using can be achieved after detaching.