The invention discloses an argon shielding device for titanium material welding, belongs to the field of welding in the machinery industry, and solves technical problems of hydrogen absorption, oxygen absorption and the like of weld joint molten pools during titanium material welding. The device comprises two parts, namely, an upper gas shielding cover and a lower gas shielding tank, wherein the upper gas shielding cover structure comprises a welding torch 1, a hose clamp 2, a tail drag cover 3, a vent pipe 4 and a porous plate 5; the argon arc welding torch can be tightly clamped by the hose clamp 2, the tail drag cover 3 is connected with the hose clamp, and a plurality of small holes are formed in the bottom of the vent pipe 4; the lower gas shielding tank structure comprises a grooved steel plate 6, a porous plate 7 and a gas inlet pipe 8. A usage method of the device comprises steps as follows: a piece of weldment is placed between the upper gas shielding cover and the lower gas shielding tank, argon is fed from upper and lower sides respectively, the argon arc welding torch is fixed according to an operation procedure, the distance between the welding torch and the workpiece is adjusted, and welding is performed after air in the shielding tank is replaced. With the adoption of the device and the method, argon flows stably, the welding joint surface shielding effect is very good, the structure is simple, the cost is low, the manufacturing cost is greatly saved, and production efficiency and quality are improved.