Composite board frame type mud press-filter dryer

The utility model relates to a composite plate frame type sludge filter-pressing dryer. An auxiliary plate frame with a matched shape and a small thickness is respectively between every two main plate frames; a hollow region of a frame body of each auxiliary plate frame is formed from side frames on the circumference, a whole elastic diaphragm is respectively combined on the front and the back parts of the frame, and the inside of the hollow region of the frame body can form a sealed space and a sludge inlet communicated with the front and the back parts; the corner parts of each auxiliary plate frame are provided with sewerage discharge holes communicated with the front and the back parts; the periphery of the frame body of the auxiliary plate frame is respectively provided with a hot air inlet hole and a hot air outlet hole which are both communicated with the sealed space; external hot air can be input into the sealed space and heated, the front and the back diaphragms are forced to stretch, and water in sludge inside a filter chamber can be vaporized; the dryness of the sludge can be increased, the volume of the sludge can be reduced, and the subsequent handling cost, the retreatment cost, etc. can be reduced.