The invention relates to a device for electrolysis, pressure filtration and dehydration of fine coal. The main structure of the device consists of a feeding box, an electrolyzer, a copper electrolysisring, a copper electrolysis plate, a copper electrode net, a stirring machine, a suction pump, an electrolysis electric control box, a pressure filter, a hydraulic telescopic cylinder, a pressure filtration push-pull plate, a bracket, an air compressor, a pressure filtration electric control box, a pressure filtration plate, a pressure filtration internal plate, an infusion tube, a water inlet pipe, trapezoidal convex patterns, and positive and negative electrode wires. The device continuously performs liquid feeding, electrolysis, transfusion, pressure filtration, secondary electrolysis, dehydration, blowing filter cake to fall off and filter cake collection, finishes the operations once, and integrates machine, electricity, water and gas to achieve mechanization, automation, computer program control and liquid crystal display, so that the dehydration efficiency of the fin coal is greatly improved and the working efficiency can be improved by 2 to 3 times compared with the prior art.The device is an ideal device for the electrolysis, the pressure filtration and the dehydration of the fine coal, and can be applied to the dehydration of other mineral powder.