The invention provides a pollution-flashover-preventing cleaning device and a multifunctional pollution-flashover-preventing cleaning machine, and relates to the technical field of power transmission line pollution flashover prevention. The pollution-flashover-preventing cleaning device comprises a crawler wheel, a fixing ring body, a connecting arm, a cleaning brush ring, a power supply unit and a motor. The fixing ring body is installed on the two sides of the crawler wheel. One end of the connecting arm is installed on the side of the fixing ring body, and the other end of the connecting arm is installed on the side of the cleaning brush ring. The cleaning brush ring is connected with the fixing ring body through the connecting arm. The power supply unit and the motor are installed inside the fixing ring body, and the fixing ring body further contains a pollution-flashover-preventing cleaning agent. The crawler wheel is driven by the motor to move forwards, and the pollution-flashover-preventing cleaning agent permeates the surface of an outdoor insulating facility, so that primary cleaning is conducted; and then the cleaning brush ring is driven by the motor to rotate, so that the pollution flashover is further cleaned away. According to the pollution-flashover-preventing cleaning device and the multifunctional pollution-flashover-preventing cleaning machine, by means of simple operation, the power supply reliability, the working efficiency and the construction safety can be improved, and the construction operation strength can be reduced.