The invention belongs to the technical field of tantalum sheet preparation and discloses a preparation process of a porous tantalum sheet. An electrolytic corrosion mode is adopted for preparation. The preparation process comprises the steps of preparing a tantalum sheet as an anode electrode and platinum as a cathode electrode, and putting the anode electrode and the cathode electrode into an electrolytic cell; preparing an electrolyte solution with ethyl alcohol and a conductive agent, and putting the prepared electrolyte solution into the electrolytic cell, wherein the conductive agent is chloride which can be dissolved into the ethyl alcohol; after the distance between the anode electrode and the cathode electrode, fixing the anode electrode and the cathode electrode to the electrolytic cell; and connecting the anode electrode and the cathode electrode to a positive pole and a negative pole of a direct-current power source correspondingly, and starting electrolytic corrosion to prepare the porous tantalum sheet. The obtained porous tantalum sheet is large in number of holes; the holes are distributed relatively uniformly; the diameters of the holes are each at the micron level;and the tantalum sheet can be used as an excellent raw material in all relevant fields.