Abstract: A WEDM machine tool for machining a disc-shaped porous part, comprises a workbench, a central stand column, a rotary device, a plurality of wire rack assemblies and a wire feeding mechanism comprising a bottom plate, a wire rack arranged on the bottom plate and a radial driving mechanism for driving the wire rack to move in a radial direction on the bottom plate; and the wire rack is a “[”-shaped rack with an opening oriented to the central stand column; and the wire feeding mechanism comprises a first guide wheel assembly arranged on the workbench to guide an electrode wire into and out of a wire winding barrel, second guide wheel assemblies arranged on the radial driving mechanism and the wire rack, a third guide wheel assembly arranged on the central stand column and a fourth guide wheel assembly arranged between two wire rack assemblies.