The invention relates to an in-situ reaction precipitation manufacture device and process of a lotus-root-shaped porous metal material. The process comprises the steps of coating a water-containing coating on an inner wall of a casting mould under the atmosphere condition, pouring molten metal liquid into the casting mould and manufacturing the lotus-root-shaped porous metal material with high porosity, controllable pore size and long and straight pores through directional solidification. The in-situ reaction precipitation manufacture device mainly comprises a smelting furnace, a stopper rod and control system, a temperature measurement and control system, a guiding pipe, a crystallizer and cooling system, a casting mould and fixing device and the like. The shortcomings of a 'pressurized dissolving precipitation method' are overcome, production under high-pressure hydrogen and other high-pressure atmospheres is not needed, and the safety is good. The operation is simple, and the casting process is visible. The lotus-root-shaped porous metal material manufacture device is simple in structure, few in investment and simple and convenient to operate, the production cost can be reduced, and high efficiency and continuity of the manufacture process are achieved.