The invention particularly discloses a hydraulic supporting device for a fully-mechanized coal driving workface, and solves the problem that no supporting device is provided for realizing synchronous and continuous operation of driving and supporting of the fully-mechanized coal driving workface at present. The device comprises a plurality of supporting top beams, wherein an oil cylinder is sleeved in each supporting top beam; adjacent ends of the oil cylinders are fixed to the supporting top beams, and the other ends of the oil cylinders are fixed with telescopic beams; a hydraulic support column is vertically fixed to one side of each telescopic beam; the upper end face of each supporting top beam is provided with a groove; sliding bodies are connected both in the groove and on the lower end face of the supporting top beam corresponding to the groove through iron chains; and each sliding body on the lower end face of the supporting top beam is provided with I steel and the upper leg of the I steel slides on the sliding body. The device can keep the original stress of a tunnel and the rock formation unchanged after excavation in a short time and provide a safe environment for workers and equipment for the fully-mechanized coal driving workface so as to greatly improve the supporting effect and reduce the labor intensity; and the device has the advantages of simple processing and low cost.