The invention discloses a protecting device for a dust removal system of a coal charging car. Cutting-off and diffusing of raw gas can be synchronously conducted, and the situation that pipeline explosion of the dust removal system is triggered under the condition of power failure or draught fan failure is avoided. A cover plate capable of blocking a middle pipeline is arranged on the middle pipeline between a dust collecting pipe and a dust collecting connecting pipe, the cover plate is fixedly provided with a rotary shaft I hinged to the middle pipeline, a connecting rod I is vertically fixed to the rotary shaft I, and the cover plate is further connected with an opening and closing mechanism for driving the cover plate to rotate along the rotary shaft I. A top cover plate capable of sealing the upper end of the dust collecting pipe is further included, the top cover plate is fixedly provided with a rotary shaft II hinged to the dust collecting pipe, a connecting rod II connected with the connecting rod I through a rope I is vertically fixed to the rotary shaft II, and linkage of the top cover plate can be achieved when the connecting rod I rotates. A pressure relay is fixed to the side wall of the dust collecting connecting pipe.