The invention discloses an automatic cleaning device and method for feeding holes of filter plates. Sliding plate seats are mounted on the upper parts of slideways of plate pulling devices positionedon the two sides of a press filter; a framework body is mounted on the sliding plate seats; the plate pulling devices and the framework body are mounted on the same sliding plate seat; a driving clamping lug is mounted on an air cylinder body piston rod; a fixed clamping plate is welded to a support frame; a curved cantilever is connected with the fixed clamping plate through a positioning pin shaft; a driving hole is formed in the upper end of the curved cantilever; the driving hole is provided with a driving pin shaft and is connected with the driving clamping lug; a material pushing flangeis arranged at the lower end of the curved cantilever. The cleaning method comprises the following steps: completely and automatically controlling cleaning operations by a PLC (Programmable Logic Controller) program, wherein the cleaning operations are as follows: pulling a first filter plate open by the plate pulling devices; pausing the filter plate for 3 to 6 seconds when a distance from the filter plate which is pulled open to an end point is 100 to 200mm; turning on an air cylinder solenoid valve to enable air flow to enter an air cylinder body so as to push the piston rod to move forwards and drive the curved cantilever; enabling the material pushing flange to quickly enter the feeding holes in the filter plates through the curved cantilever according to an angle of an inclined plane; pushing precipitated materials in each feeding hole out; sequentially and circularly pulling the whole filter plates mounted on the press filter open to ensure that automatic cleaning is completed.